• en
  • fr
  • ja

Archive | Tires

Tires

Endurance Casings for 700C x 38 and 700C x 55

You asked for it… Many customers requested our Barlow Pass with the Endurance casing. It makes sense – 700C x 38 is a versatile size. If your rides are littered with glass, steel wires or goatheads, the Endurance casing is going to be your friend. You get a tire with much of the speed and comfort of our other Rene Herse tires, yet it’s considerably tougher than the Standard or Extralight casings.

The Antelope Hill is another prime candidate for the Endurance casing. Call it 700C x 55 or 29″ x 2.3″ as you wish – it’s a tire for monstercross and mountain bikes that are ridden on gravel roads (and paved ones, too).

Most of the time, the sheer volume of this tire (and associated low pressure) will ward off sidewall cuts and punctures. Yet by their nature, the Antelopes invite you to take them places you wouldn’t go otherwise. And then the extra protection of the Endurance casing can be great reassurance…

These Rene Herse tires are available with Endurance casings:

  • 650B x 48 Juniper Ridge (knobby)
  • 700C x 38 Barlow Pass
  • 700C x 38 Steilacoom (knobby)
  • 700C x 42 Hurricane Ridge (knobby)
  • 700C x 44 Snoqualmie Pass
  • 700C x 55 Antelope Hill

Quantities of the new models are limited for now, until production catches up with demand. Click here for more information.

Continue Reading

Road.cc Reviews the Juniper Ridge 650B x 48

We like Road.cc, the British web site, because they really ride the products they test. They’ve got a number of testers, and their opinions are refreshingly unbiased and honest. At the end of each test, they ask their reviewers “Would you buy this product?” and “Would you recommend this product to a friend?”

Recently, they reviewed our Juniper Ridge dual-purpose knobbies, and tester Stu Kerton replied “Yes” to both questions. His summary explains why:“The Juniper Ridge has been designed to work just as well on the road as it does off the beaten track. I was sceptical, but to be honest they are pretty good, giving a boost to your average speed on those tarmac sections between the tracks and trails.”

Grip on gravel and in mud impressed him, too: “Cornering on hard-packed gravel, the Junipers had just the right level of grip for the knobbles to dig into the gravel so you could blast round at speed. […] They grip well on soft mud and the tread doesn’t seem to hang onto any dirt either, shedding it before it can become compacted between the knobbles. The only place they did suffer a bit was on wet, sticky chalk, which could clog up the tread.” But then, I suspect that any tire will clog up in that type of sticky mud…

It’s exciting when testers enjoy our tires as much as we do. Rather than tell you more about the test, why not read the full review for yourself at road.cc?

Continue Reading

Why Only Black Tread?

Autumn means colder temperatures and rainy weather, here in the Cascade Mountains and in many parts of the world. More than ever, the grip of our tires is on our minds. Why do all Rene Herse tires have black tread? Colorful treads can look nice, but black rubber offers the best grip.

That is one reason why all car tires today are black. In the early days of motoring, tires were made from natural rubber, which is white or gray. (That is why the famous Michelin man is white…) By the 1910s, it was becoming apparent that white rubber didn’t last well, and tire makers discovered that adding carbon black to the rubber made it last much longer. As a positive side effect, it increased the tire’s grip, too – and it made the tires black. Even today, you can get car tires in many colors, but they are considered a novelty and not intended for daily use, much less for performance driving.

It may come as a surprise that the color of rubber and plastic affects many other properties, too. For example, gray resins are stronger than black or colored varieties. That is why the frames of Berthoud saddles are gray. With rubber, blue appears to be the least durable – which is why the blue hoods for old Mafac brake levers are almost unfindable today. And red backpacks fade far more quickly than other colors…

The reason is simple: Colors are additives, and often, surprisingly large amounts of the colorants are needed to create the color. This often changes the physical properties of the raw material. The black color of tires works the opposite way: Carbon black is an additive chosen for its performance-enhancing properties, and it just happened to change the color to black.

Before we made our Rene Herse tires, we rode tires from many makers. When I was racing in the 1990s, Vittoria introduced their ‘Professional All Weather’ model with softer green rubber on the shoulders. This was supposed to be grippier when leaning the bike into wet corners. It seemed like the perfect tire for Seattle’s infamous rainy season.

We tried the ‘All Weathers,’ and immediately scared ourselves: They seemed to grip fine at first, while we were still riding on the black center tread. Leaning further, grip was lost very suddenly as we transitioned to the green rubber. Then TOUR magazine did one of their famous tire tests. They measured tire grip on wet roads and confirmed that the ‘All Weather’ was less grippy than Vittoria’s standard, all-black tires! We never found out what the Italians were thinking when they developed these tires. I recall a big marketing push with all kinds of colors around that time, but it didn’t last long. Today, all Vittoria tires have black tread again.

Later, we imported the first supple, wide 650B tires from Japan. Made to resemble classic French rubber, the first model was available only in red and white. We loved the supple casings, but we found that in the wet, the white version was noticeably lacking in traction. Riding the red model, we also felt the grip bleed away earlier than we expected. We requested a special run of tires with black tread, and those gripped much better.

Of course, black tread alone isn’t a guarantee for excellent traction. I recall one tire from a small company that would spin when accelerating from a stop on cold, wet (but clean) pavement. Clearly, not all rubber is made equal.

When we first talked to the engineers at the tire factory in Japan about the tires we wanted to make, they showed us many beautiful colors. There was a very attractive tea green… When we asked about the performance, the engineers left no doubt: “Black has the best grip.” What about the colored treads? “It’s all about fashion. It allows small companies to offer tires that are different from the mainstream.”

There is nothing wrong with fashion, but for us, performance is more important. On the steep, twisty descents of the Cascade Mountains, we need tires that grip. And fortunately, Panaracer’s top-level tread rubber is among the grippiest you’ll find anywhere.

Of course, there is much more to making a tire grip than just the tread compound. Our herringbone tread pattern has many ribs that interlock with the road surface. When we tested the herringbone tread back-to-back with slick tires, the difference was very noticeable. A supple casing also grips better because it keeps its tread in contact with the road surface. A stiffer tire will bounce more and have less traction. For our Rene Herse tires, we’ve optimized all these parameters to offer you tires with more grip than just about any other tire – on dry and wet roads.

Even with the best tires, riding in Autumn and Winter requires extra caution. There are many factors that decrease traction when it’s wet and/or cold:

  • Cold rubber is less grippy – your traction is reduced when the temperature drops. This is quite significant, especially once the temperature drops below 10°C (50°F).
  • On wet roads, tread patterns that interlock with the road surface offer the greatest benefits. With the right tires, you can lean quite far into corners (top photo) – if the asphalt is clean.
  • After the first rain, the water mixes with dust, oil and other airborne pollution to form a very slippery surface layer. Use extreme caution when it hasn’t rained in a long time.
  • Your tires stay wet for a while after you ride through water. Remember this when you cross a wet patch on the road: Your tires may still be wet in the next corner, even if the road surface there is dry.
  • Painted traffic markings on the asphalt can be very slippery in the wet. Metal surfaces – grates, manhole covers, railroad tracks, plates covering trenches at construction sites – are even worse. Avoid them if you can. If you must ride over them, straighten your bike before you reach them, so you aren’t leaning while you are on the slippery surface.
  • Scan the road for shiny oil that has dripped from cars with leaky crankcases.
  • Tire sealants that use latex – which means most brands – won’t seal when it’s cold. (Latex doesn’t cure well when it’s colder than 10°C/50°F.)
  • Snow and ice require special considerations.

We enjoy riding our bikes year-round, so we’ve developed components that perform well in wet and cold conditions, not just when it’s dry and warm. With the right equipment and skills, riding in all weather can be safe and enjoyable.

Further reading:

P.S.: I apologize for re-using the same opening photo. There aren’t many that show us cornering hard in the rain – when it’s wet and cold, we prefer keep going to stay warm, rather than stop for photos!

Continue Reading

How Fast are Rene Herse Tires?

How fast are our tires? We know that the casing, and not the width, determines a tire’s speed. When I rode Paris-Brest-Paris on 42 mm-wide tires (above), I knew that I wasn’t giving up any speed over narrower rubber. But in absolute terms, how fast are our Rene Herse tires?

Manufacturers’ claims always are taken with a grain of salt… So let’s look at two independent tests of our tires. They still list the old ‘Compass’ name, but the tires tested were the same as the current Rene Herse models.

The respected German magazine TOUR found our Bon Jon Pass as one of the five fastest tires they’ve ever tested. TOUR tested the Standard model. The much more supple and speedy Extralight would have fared even better.

TOUR’s test rig is a pendulum that rolls the tires back and forth. The longer the pendulum swings, the lower the rolling resistance.

Like all tests that don’t include a rider, this test measures only losses due to deformation of the tire (hysteretic losses). In the real world, there are also suspension losses as vibrations are absorbed by the bike and the rider. Wide tires vibrate less than narrow ones, so they tend to roll even faster than these tests suggest.

In any case, the result is clear: In TOUR’s test, the Bon Jon Pass is one of the fastest tires in the world, closely matching the best racing tires. Being 9-12 mm wider than the racing tires doesn’t make the Bon Jon Pass any slower.

What’s the best gravel tire? – 10 models in comparison

How about comparing our tires to other wide tires? Gran Fondo magazine recently tested ten popular gravel tires. Rolling resistance (and puncture resistance) were tested by Schwalbe’s engineers in the company’s test lab.

Our Barlow Pass Extralight had the lowest rolling resistance (red bar) of all tires in the test. (100% is the best in the test.)

The engineers at TOUR and Schwalbe are among the most respected in the cycling world. Their tests show that our casings are among the most supple, and roll as fast or faster than the best tires in the world.

On real roads, the advantage of supple tires is even greater: Not only do they absorb less energy as they flex, they also vibrate less. And that reduces the suspension losses. Both effects work in tandem: Supple tires have less tire deformation and less vibration. As a result, the greater speed of supple, wide tires becomes very noticeable when you ride on real roads. When you try different tires back-to-back, you realize that tires are the biggest performance upgrade you can make to your bike.

A little more about the Gran Fondo test: The testers were impressed by the “superb levels of comfort” of the Barlow Pass and called it “almost as nice as flying.” They also were surprised how much grip the supple tires offered on gravel and dry dirt roads. Of course, reading that makes us happy, even if it just confirms what we’ve found in our own testing.

Further reading:

Continue Reading

New Sealant for Rene Herse Tires

Tubeless tires have changed what we can do on a bike. When the terrain is really rough, not having to worry about pinch flats allows us to run lower tire pressure for more comfort, more traction and more speed. (The speed comes from the lower pressure on rough surfaces, not from the tubeless setup itself.)

Setting up tires tubeless can be a hassle – and high-performance tires require more diligence yet. Everything that makes supple tires so fast and comfortable also makes them harder to set up tubeless: The ultra-thin sidewalls aren’t air-tight, and the tires are so floppy that the bead can be hard to seal against the rim. Supple tires need sealant to close those microscopic pores in the casing and to constantly seal the tire against the rim.

There are many tricks to setting up tires tubeless, and the right choice of sealant is one of them. Many sealants are intended for mountain bike tires with stiff casings that are covered with a thick layer of rubber, making them airtight on their own. The sealant is only intended to close small punctures, not to make the tire itself airtight and seal it against the rim. Those sealants can work OK with supple high-performance tires, but we wanted a better solution.

Over the last two years, we’ve worked with Panaracer in Japan to develop a sealant that is specifically formulated for the supple sidewalls of Rene Herse tires. (The sealant works equally well with Panaracer tires and other brands.)

The Seal Smart sealant uses natural latex and walnut shells to make the tire airtight and seal it against the rim. Thanks to these ingredients, it’s non-toxic and low in allergens. Clean-up is easy, too.

Most of all, it works really well. With every tire we’ve set up so far, the tire sealed almost instantly and held its air for weeks without re-inflating. We’ve tried it on tires that were returned under warranty because the sidewall didn’t seal. (This happens very rarely when the rubber coating is a bit too thin.) Bubbles appeared on the casing, and the tires continued to lose air. With the new Seal Smart, two tiny bubbles appeared at first, but the tires sealed fine. We wiped off the bubbles, and they didn’t reappear – the tires were ready to ride.

Of course, every installation is different, and we cannot guarantee a successful tubeless installation. Especially with supple tires, it pays to be extra-diligent when distributing the sealant inside the tire to make sure it goes into every crack. And make sure to shake the sealant vigorously for a minute or more to distribute the solids really well: If you’re just injecting white water into the tire, it won’t seal…

The new Panaracer Seal Smart comes in 500 ml (17 oz) bottles – enough to set up 4-6 tires and replenish your sealant frequently. It is in stock now.

Further information:

Continue Reading

Rene Herse 700C x 44 with Endurance Casing

We developed the Endurance casings for our Rene Herse tires based on requests from gravel racers like Ted King (above), who need tires for truly harsh conditions. A race like Dirty Kanza traverses 200 miles of sharp stones in the Flint Hills of Kansas. The lead racers travel at high speeds in densely packed pelotons, unable to see the road ahead – and thus unable to avoid hitting big and sharp rocks. The event becomes a race of attrition. If you flat and are lucky, your plug holds, your CO2 cartridge inflates the tire, and you can chase back on. More likely, you see the peloton vanish into the distance.

It’s for this type of event that we’ve introduced our Endurance casing. It’s a beefed-up version of our renowned Extralight casing: We use the same ultra-thin and ultra-supple threads, but push them closer together to obtain a denser weave. Then we add a puncture protection layer from bead to bead that reinforces not only the tread area against punctures, but also the sidewalls against cuts.

For even tougher conditions, we offer the Endurance Plus casing with thicker threads for even more cut resistance, plus the same puncture protection layer as the Endurance casing. It’s probably overkill for most rides and races, but there are times where you gladly give up a little speed for the peace of mind of not having to think about your tires at all.

We shipped a small quantity of Rene Herse tires with Endurance casings as soon as possible, so racers could use them in Dirty Kanza and other races. This also allowed us to get valuable feedback from the field.

Ted King (leading the pack in the photo above) rode the Hurricane Ridge Endurance Plus to a formidable 8th place in this year’s Dirty Kanza against international competition of professional riders. In the past, the ‘King of Gravel’ had suffered from flats in every edition of this epic race – but not this year.

Others had similar experiences. One customer wrote:

“I used the Steilacoom Endurance tires and had no problems or flats on the DK200 course this year. I did not feel that I had to brake and descend with extra caution, but felt confident to just let them roll. I will now continue to ride these tires, dropping the pressure for added comfort and better rolling resistance, and see where the limits are.”

Another racer commented:

“I would like to let you know on how amazed I was in yesterday’s Dirty Kanza riding your Steilacoom tires with the Endurance casing. Hassle free. No flats, no nothing, all good, and supple riding!”

And:

“Thank you for the expedited shipping so I got the tires in time for the race. You guys are as awesome as your tires…”

The first shipment of Rene Herse tires with Endurance casings sold out almost immediately. We’ve now received another shipment, and all models are back in stock.

We are also introducing two new models, the 700C x 44 mm Snoqualmie Pass Endurance and Endurance Plus with our smooth all-road tread. For dry rides and races where you won’t encounter mud, these tires are a great choice. They complement the knobby 700C x 42 mm Hurricane Ridge to offer a quiver of tires that will handle all conditions. They are ideal not just for racing, but also for adventures where you don’t know what you will encounter.

In addition to our Standard and Extralight tires, we now offer the following tires with Endurance and Endurance Plus casings:

  • 700C x 38 mm Steilacoom knobby (Endurance)
  • 700C x 42 mm Hurricane Ridge knobby (Endurance; Endurance +)
  • 700C x 44 mm Snoqualmie Pass all-road (Endurance; Endurance +)
  • 650B x 48 mm Juniper Ridge knobby (Endurance)

Click here for more information about our Rene Herse tires.

Photo credit: Dustin Michelson/Gravelguru (Photo 1).

Continue Reading

Tune Your Tires!


With wide tires, you can tune the ride of your bike to the terrain and to your personal preferences. This gives you options that simply did not exist in the past.
Gone are the days when we inflated our narrow tires to the maximum pressure and rode on rock-hard rubber. Even with narrow tires, you can lower the pressure a bit to get a (slightly) more comfortable ride. Of course, there is only so much you can do – the feel of the bike won’t really change. There is simply too little air, and you’ll get pinch flats if you reduce the pressure enough to make a real difference. The only way to transform the feel of a racing bike is to get different tires – that’s why professional racers have always run hand-made tubulars with supple casings (well, at least since the 1930s).
With wide tires, supple casings also make a huge difference. In addition, you can choose your tire pressure over a wide range: The 54 mm-wide Rene Herse Rat Trap Pass tires that Hahn is running in the photo above work great at pressures between 20 and 55 psi. That means you can cut the pressure to almost a third of the maximum, if you want. (For comparison, this is like running narrow 120 psi racing tires at 45 psi. Don’t try this with 25 mm tires!)

With wide tires, you can tune the feel of your bike by adjusting the tire pressure. The same tire will feel completely different depending on how hard you inflate it. This is something that you really start to notice with tires that are wider than 40 mm.

At 55 psi, my Firefly with its Rat Trap Pass tires feels firm and buzzy like a road bike on narrow tires. There is no noticeable flex in the tires, no matter how hard you corner, or how fast you sprint. You’ll feel every detail of the road surface almost unfiltered. The extra air does take off some of the harshness, and the extra rubber gives you more grip, but the feel is similar to a bike with narrow, high-pressure tires.

Why doesn’t the 54 mm Rat Trap Pass feel wallowy like a 25 mm tire at 55 psi? If you think of the tire as an air spring – a piston in a cylinder – then pressure is only one factor. The other is the diameter of the air cylinder. To compress a 54 mm tire takes more force than to compress a 25 mm tire, even if both are inflated to the same pressure.
Even with wide tires, you can get the feel of narrow tires, if you inflate them to (relatively) high pressure. But you also have options to tune your bike by letting out some air.

At first, not much is happening – 55 psi is far more than most riders will ever want to use in these tires. At 30 psi, you still get the firm feel of a ‘road bike,’ but more shock absorption and even better traction. This is the pressure I ride on very smooth roads.

At 25 psi, the tire has a lot more compliance. Now it really feels like an ultra-wide tire. It still corners great, but you can go over bumpy roads and really feel the suspension. This is the pressure I use on most paved roads.

On rough gravel, I let out even more air. At 20 psi, the tire really floats over the gravel. This is how I imagine a rally car with ultra-expensive shock absorbers feels: ‘breathing with the surface,’ gently going up and down over bigger undulations, but insulating you from the smaller bumps and vibrations. It’s an amazing feeling, and, without the bike bucking under you, you can put down power at all times. It’s fun to ride at ‘road’ speeds on rough gravel.
And even at this low pressure, there is enough air to prevent the tires from bottoming out. Even with tubes, I don’t get pinch flats – unless the terrain is really rough and rocky and speeds are ultra-fast.

When you’re descending at very high speeds on very rough terrain, you’ll have to increase the tire pressure a bit to avoid bottoming out too often. Even if you run your tires tubeless, you risk cutting your tires and damaging your rims if you bottom out too often and too hard.

When you return to pavement, 20 psi isn’t enough. The tire starts to squirm and run wide in corners. When you rise out of the saddle, it feels wallowy as it compresses under the thrust of your pedal strokes. And if you really push the limit, the tire can collapse in mid-corner.
Back on pavement, I inflate the tires back to 25-30 psi. If my ride includes both pavement and gravel sectors in quick succession, I often just keep the pressure around 25 psi, so I don’t have to mess with it.

Tire pressure is not just about shock absorption – it also affects the power transfer of your bike. A frame that is too stiff for the rider’s power output and pedaling style is harder to pedal – a little compliance smoothes out the power strokes and allows the rider to put out more power. We call this ‘planing,’ but it’s hardly a revolutionary idea.
Usually, that compliance comes from the frame. That is why high-end, superlight bikes perform so well, even on flat roads where the weight doesn’t matter. The lighter frames use less material, which makes them more flexible. Conversely, ultra-stiff bikes can feel ‘dead’ and hard to pedal to many riders.
With wide tires, that compliance can come from the tires, too. When we tested the Jones (above), we found it to perform wonderfully with its tires at ‘gravel pressure.’ When we aired up the tires for a fast road ride, the bike suddenly felt sluggish. This is the opposite of what conventional wisdom might tell you, but when we lowered the tire pressure again, the wonderful performance of the Jones was back. This has nothing to do with rolling resistance – it’s all about how much power we could put out thanks to the added compliance in the system. The Jones ‘planed’ best with its tires at relatively low pressure. This means that you can use tire pressure to adjust how much ‘give’ you have in your bike’s power transmission. I’ve found this a useful tool to get the most out of many Bicycle Quarterly test bikes.
Speaking of rolling resistance – don’t tires roll slower when you let out air? At least with supple tires, tire pressure makes no discernible difference, not even on smooth roads. As long as you have enough pressure that the bike is rideable, your tires roll as fast as they do at higher pressures. And on rough roads, lower pressures will be faster, both because the suspension losses are reduced and because you can put out more power.

Tuning your tires is fun. It optimizes your bike for your preferences and for the terrain you ride. Of course, tire pressure first and foremost depends on your weight – the numbers in this post assume a bike-and-rider weight of about 80 kg (175 lb).

Tire pressure also depends greatly on the casing of your tires. The values in this post are for Rene Herse Extralight tires. With Standard or Endurance casings, you can run about 10% less pressure. With a stiffer casing, you run even less air, all the way to airless tires that run at zero pressure. As your tires get stiffer, you lose the ability to tune your ride, because air pressure plays a smaller role in supporting the bike-and-rider’s weight. The beauty of supple tires is that air pressure is the main component that holds up the weight of bike and rider. This makes it easy to tune your tires.
Rather than inflate your tires to a set number, experiment with tire pressures to see how this changes the feel of your bike. Also remember that the gauges on pumps aren’t always accurate – use them only to replicate a setting that you’ve found useful in the past, rather than try to inflate your tires to an exact pressure. Once you’ve found values that work, you can quickly change the feel of your bike based on where you’ll ride and how you want your bike to feel. This makes cycling even more fun!
Further information:

Continue Reading

Oregon Outback: the event that changed all-road bikes


It’s hard to believe that the first Oregon Outback, that incredible 363-mile gravel race, was just five years ago. It’s almost like we live in a different world now, so much has changed…

Back then, the idea of running a race that traversed the entire state of Oregon from south to north – on gravel roads! – seemed completely outrageous. So seemed the idea of riding the entire distance non-stop. And the idea of riding a road bike on these gravel roads. More than one rider told me at the start that they were astonished to see me on my Rene Herse for this grueling event. I am sure Ira Ryan, on his Breadwinner B-Road, heard similar comments.

A joyful crew rolled out of Klamath Falls on Memorial Day weekend in 2014. Most were on mountain bikes equipped with bikepacking gear. Nobody knew what to expect. Would it take two days or a whole week to reach the Columbia River at the other end of the state? There were few options for bailout; there was no support – this was a real adventure.

It did not take long for the race positions to shake out. By the time we reached Switchback Hill (above), there were three riders at the front. Ira Ryan was the favorite, having won the Trans Iowa race in his home state. He was riding on 35 mm tires – which was considered wide! Another strong racer was on a mountain bike. He had opted for narrower 700C tires. I was on the widest rubber, with our just-released 650B x 42 Babyshoe Pass Extralights.

I couldn’t match the speed of the other two, not helped by a broken hand that was still in a brace… With almost 300 miles to go, I settled into my own pace.

As the day wore on and the ground got softer, I could see Ira’s tracks swerving wildly from side to side. There was only one set of recent tracks, so I knew that the second rider had abandoned by now… Even on my 42 mm tires, I was struggling. And yet, on the (even softer) edge of the road, I could see the tracks of two mountain bikers who had come through here a few days earlier. Their wide tires had enabled them to ride in a straight line…
A few hours later, I reached one of the three towns on the route, where I met Ira Ryan’s camera crew. I learned that he was just 15 minutes ahead. Even though I had struggled on the loose surface, I had made up a lot of time – probably because my tires were wider.

The solitude of the long day on the road gave me time to think. I remembered how the Paris-Dakar Rally had fascinated me as a teenager. I could see parallels to the Oregon Outback: In the early Dakars, competitors used 4×4 trucks, which seemed the best vehicles to traverse the deserts of northern Africa. Then Porsche developed a four-wheel-drive version of their 911 sports car and won the Dakar in their first attempt (above).
Here in the Oregon Outback, it was obvious that the wide tires of mountain bikes provided an advantage on very loose gravel. Yet it was also clear that the mountain bikes themselves were holding back their riders on what really were roads after all. For the Dakar, Porsche had allied four-wheel drive with sports-car performance. Could we do the same and combine the wide tires of a mountain bike with the performance of a road bike?

By the time I climbed Antelope Hill, I had a plan: We’d take our all-road bikes beyond the 42 mm-wide tires that we’d been riding until then. I was certain that ultra-wide road tires would transform our bikes’ performance on gravel and other loose surfaces.

The last miles of the race went by in a blur. When I saw that Ira had written “Go Jan!” into the gravel, I knew I was on the home stretch. (Thank you, Ira, for encouraging me!)

After losing much time in the middle of the night – I back-tracked for more than an hour to make sure that I was on course – there was no hope of catching Ira. (He was faster anyhow!) My goal now was to finish in 30 hours. I redoubled my efforts and let the bike fly on the descent to the Columbia River.

I made my goal – and took the photo above after realizing that there was nobody at the finish. But I also wondered how much faster (and more fun) the ride would have been on wider tires.

Back in Seattle, I went to work on making road bikes with ultra-wide tires. My only concern was that nobody had ever ridden supple road tires that wide. Would they even be rideable? Or would the wheels bounce down the road like basketballs? Before we invested in tire molds, we needed to test this. So I asked the engineers at Panaracer in Japan (who makes our tires) to make prototype tires with our Extralight casing, using a mountain bike tire mold. A few weeks later, eight completely hand-made tires arrived. Now we had super-supple knobbies, but we wanted road tires.
The next step was to send the prototype tires to Peter Weigle, the famous framebuilder and constructeur. Years ago, he built a machine to shave the tread off tires, before we offered wide high-performance tires with just the right amount of tread. Peter shaved off the knobs to turn our prototype tires into slicks (above). The result were probably the most expensive bicycle tires ever made, but now we finally had 54 mm-wide, supple, slick tires that we could test.

Alex Wetmore had a 26″ bike that fit tires this wide, his Travel Gifford. We borrowed it and installed the new tires. If you look carefully, you can still see where the knobs were on the prototype tire above. It’s hard to describe our excitement: We were about to try something completely new.
enduro_allroad_cobbles
Then we started testing the new tires. On gravel, the 54 mm-wide tires were amazing. The bike just cruised over stuff that would have meant serious ‘underbiking’ on 42 mm tires. It was fun!
enduro_allroad_web1
What surprised us even more was the new tires’ performance on pavement. The grip was just incredible, both because there was so much rubber on the road and because the soft, supple tires no longer skipped over bumps. On this difficult descent in Leschi, you usually have to be cautious and brake for the bumpy turns. With the new tires, we pedaled as hard as we could, yet we weren’t able to reach the limits of grip. Did I say the testing was fun?

Knowing that the ultra-wide road tires worked as well as we had hoped, we ordered molds for two new tires: the Rat Trap Pass 26″ x 2.3″ and the Switchback Hill 650B x 48 (above). Both were revolutionary at the time, by far the widest high-performance road tires anybody had made in more than half a century. (Some very early pneumatic tires had been quite wide, too.)

There were no road bikes yet for such wide tires, so we worked with Firefly to make us a custom titanium road bike designed around the 26″ Rat Trap Pass tires. We took it to 13,000 ft (4000 m) on the Paso de Cortes in Mexico (above), where it performed even better than we had hoped. (Testing the new tires was definitely fun!)

26″ wheels make sense for tires this wide, but the 650B wheel size had more traction at this point – that is why we introduced tires for both wheel sizes. The next step was obvious: Bike makers needed an inexpensive OEM tire before they could commit to making bikes for tires this wide. As a small company specializing in high-performance components, this wasn’t something we were equipped to do.
Fortunately, others were taking note of our pioneering work. In 2016, WTB launched its Byway tires. Now there were ultra-wide 650B road tires at OEM price points. Bike manufacturers were quick to act, and before long, almost every bike maker designed bikes around this tire size. Today, the size introduced with our Switchback Hill tires has become a new industry standard.

It’s hard to believe that all this started just 5 years ago, with the first Oregon Outback, that incredible 363-mile gravel race.

Continue Reading

New Tires: Hurricane Ridge and Endurance Casings


Working with Ted King, winner of last year’s Dirty Kanza gravel race, has added a new perspective to our R&D. We’ve got a lot of experience riding gravel, even racing it, but today’s mass-start races aren’t the same as exploring the Cascade Mountains on forest roads, or even racing the 363-mile cross-state Oregon Outback during the early days of gravel racing.

Like all racers, Ted wants the fastest bike he can get, and supple tires make a greater difference than almost any other component choice. Depending on the surface, Ted has been racing our 42 mm Snoqualmie Pass (Landrun 100, 2nd place), 35 mm Bon Jon Pass (Belgian Waffle Ride, 3rd place) and 38 mm Steilacoom knobbies (Epic 150, 1st place).

For Dirty Kanza and similar big events, Ted asked for a tougher tire. When you race in a peloton, you don’t see where you are going. It’s inevitable that you’ll hit some rocks and holes that you’d go around if you were riding by yourself or in a small group. And unlike the smooth gravel often found in New England (above), some of the rocks in Kansas are awfully rough and sharp.

How do you make a sturdier tire without giving up the speed and wonderful ride of our Rene Herse tires? For our new Endurance tires, we started with our Extralight casing, but pushed the threads closer together to make a denser weave for improved cut resistance. Then we added a thin protection layer all around the tire that further enhances cut-resistance and puncture protection. The darker tan color distinguishes this casing from our other offerings.

By using the same ultra-fine threads as our Extralight casing, the new Endurance tires give up only a little speed. In return, you get significantly improved resistance to rock cuts and flats. And since we start with the Extralight casing, the Endurance tires don’t weigh a ton either – no more than our already very light Standard casings. As part of our testing, Ted King has been riding prototypes with the new Endurance casing. In fact, he used them to win the Epic 150 gravel race a few weeks ago.
The Endurance casing is also a great choice for adventures where you don’t know what to expect. It’s a perfect complement to our dual-purpose knobbies that offer great performance on pavement, gravel, mud and even snow. Combine the two, and there is little your bike won’t be able to handle.

For the punishing conditions of the world’s toughest gravel races, we’ve developed the Endurance Plus casing. This uses much stronger, thicker threads, plus the same protection layer as the Endurance casing. This is a tire you might choose when the race will be a game of attrition… (Did I hear someone say Dirty Kanza?)

Gravel racers also tell us that they need wider tires, but most modern cyclocross and many gravel bikes only fit 44 mm tires (if they are smooth) or 42 mm knobbies. We already have our 700C x 44 mm Snoqualmie Pass, and now they are joined by the 700C x 42 mm Hurricane Ridge dual-purpose knobbies.

Hurricane Ridge is a great climb in the Olympic Mountains of Washington that offers two options: paved or muddy gravel. With the new dual-purpose knobbies, you’ll feel equally at home on both routes.

All this adds up to a lot of new tire models in the Rene Herse Cycles program:

  • 700C x 38 mm Steilacoom Endurance
  • 700C x 42 mm Hurricane Ridge Standard
  • 700C x 42 mm Hurricane Ridge Extralight
  • 700C x 42 mm Hurricane Ridge Endurance
  • 700C x 42 mm Hurricane Ridge Endurance Plus
  • 650B x 48 mm Juniper Ridge Endurance

With Dirty Kanza approaching, we’ve airshipped the first of the new tires from Japan to give riders and racers additional options as they prepare for this epic (and other) events. Quantities are very limited for now. If you need your tires for Dirty Kanza, select an expedited shipping method and add “Tires for Kanza” in the note field, and we’ll send out your order as quickly as possible – usually the same day. (In fact, most orders are shipped the same day.)

All our other models are in stock, too. Together with the new tires, they provide a full quiver to suit most riders and most events. Click here for more information or to order.
Photo credits: Ansel Dickey (Photos 1, 3, 10), Landrun 100 (Photo 2), Dustin Michelson (Photo 5), Ted King (Photo 8).

Continue Reading

What makes a tire corner well?


Like many cyclists, we love climbs, but we live for twisty downhills. The feeling of the bike leaning deep into a turn is something that is hard to explain, yet easy to enjoy.
[youtube https://youtu.be/mvGv9IEiDzY?rel=0&w=640&h=360]
This video clip was taken on a short descent toward Lake Washington. We know this road well, and even though we aren’t taking any risks, it’s always fun.
Obviously, one key component in making descents fun and safe are good tires. What makes a tire corner well? Here are some factors that determine cornering grip on pavement.

Most important is a round profile. That way, the tire’s behavior is always the same, no matter how far you lean the bike.
Some older tires were taller in the center – I believe the idea was that you’d roll on a narrower portion of the tire, which was thought to be faster. This caused strange transitions as the effective radius of the tire changed as you leaned the bike. Some tires have a squared-off profile. That is even worse, as amount of rubber on the road decreases dramatically as you lean the bike into the corner. Fortunately, most ‘road’ tires today are round.

Next in the order of importance is the rubber compound. A grippy rubber compound will make the tire stick better to the road surface.
In the past, we had to choose between grippy rubber that wore out quickly, or durable tires that provided heart-stopping moments when they suddenly lost traction and skipped sideways.
Today, the best rubber compounds combine excellent grip with long life, giving us the best of both worlds.

The width of the tire is also very important. More rubber on the road provides more grip – that is why racing motorbikes use wide tires.
On bicycles, there are two reasons why wider tires grip better. They run at lower pressures. This allows them to stay in contact with the road surface better. When a narrow tire skips over a bump, it loses traction. The suppleness of the casing plays a role, too: A tire that absorbs bumps better also has more traction.
Reason 2 why wide tires have more grip: The tread rubber interlocks with the irregularities of the road surface. A wider tires can interlock with more surface irregularities, so it has more grip. (No. 2 appears to be the main reason why racing motorbikes have wide tires.)

Tread patterns also contribute to the grip of a tire, or reduce it. Micro-knobs that squirm under cornering loads should be avoided. The most grippy treads are designed to provide as many interlocking edges as possible. This is especially important on wet roads, where the pure friction between rubber and asphalt is much reduced. But you’ll notice the effect even in dry corners.
Why do racing motorbikes use slick tires? Motorbikes are too heavy and too powerful to use fine ribs – they’d wear off immediately. Instead, they use very soft rubber compounds. The heavy weight and high speed of the motorbike pushes the tire into the road, thus creating the interlock with the road surface. The downside is that racing motorbike tires wear out very quickly.

Tire pressure is important, too. It’s a compromise: Pump up your tires too hard, and they’ll skip over bumps and lose traction. Run the pressure too low, and the tire can collapse during hard cornering. If your pressure is just a bit too low, you’ll just notice that the bike is running wide. If it’s much too low, the sidewall can suddenly collapse, which isn’t a good feeling at all. Fortunately, there is a wide range of ‘OK’ pressures between these extremes.

Temperature is important, too. Rubber becomes more sticky when it’s warm. On a cold day, the grip from your tires will be much reduced – even if you don’t run into ice.
Racing motorbikes warm up their tires for optimum grip, but cyclists are too light to generate significant heat when cornering.

At least as important as the outright grip of your tires is the feedback they provide as you corner. Narrow tires provide very little, but wide tires with good tread patterns give you feedback of how much grip you have in reserve. It’s subtle, but once you know what it feels like, you can sense whether you have a lot of grip in reserve, or whether you are approaching the limit. The best way to learn what this feels like is to ride on slippery surfaces – mud or snow – where you can slide at low speeds and (usually) recover from the slide. But that is a topic for another post…
In summary, to corner with confidence, you want a tire that is round, wide, supple, with a tread pattern that interlocks with the road surface, a rubber compound that grips well – and ideally, you’ll ride on a warm or hot day.

At Rene Herse Cycles, we love descending, so we’ve optimized our tires for all these factors – except the weather. You’ll have to provide that yourself.
Click here for more information about Rene Herse tires.
 

Continue Reading

The long road to dual-purpose knobbies


When Ted King recently won the Epic 150 gravel race in Missouri on our Rene Herse Steilacoom tires, many were surprised that he ran knobbies on a fast course. But there were a few muddy corners where the knobs would provide valuable grip, and Ted knew that on the smooth portions of the course, he wouldn’t give up performance, thanks to our innovative tread pattern.

When we developed our ‘dual-purpose’ knobbies, I wanted tires that roll and corner as well on pavement as they grip in mud. I can see you shaking your head: “Impossible!” For grip in mud, you need knobs. On pavement, knobs flex as the tire rolls, consuming energy and slowing the bike. And when leaning the bike into a paved turn, knobs squirm, which reduces grip and makes cornering unpredictable.


That is why for most of the history of cycling, there were knobby tires for cyclocross, and smooth tires for the road. Nobody thought of riding knobbies on the road…


When mountain bikes became popular in the 1980s, knobby tires were part of their rugged appeal, but most entry-level mtbs were ridden around town. Tire makers started to think about making knobbies that perform better on pavement. The solution was obvious: Make them less ‘knobby’ by spacing the knobs more closely. In the center of the tire, the knobs often were linked to form a continuous ‘center ridge.’ This distributed the rider’s weight over more knobs and reduced the squirm. On pavement, this worked to a degree – these tires squirmed less, but they were still no high-performance tires.

There was a drawback: When you really need knobs to dig into soft soil, mud or snow, the closely spaced knobs clog up. You spin as you would on a slick tire. These days, you don’t find many tires with center ridges and densely spaced knobs any longer, because they are worse than road tires on pavement, and just as bad in mud.


The next idea was to remove the knobs in the center of the tread. That way, you roll mostly on smooth rubber when going straight, which reduces the tire’s resistance. As long as you go straight, this works OK. When you corner on pavement, the tire grips fine at first. Then you climb onto the knobs and suddenly lose traction. It’s not exactly what you want from a high-performance tire…

If these tires had excellent performance in mud, it might be worth the trade-off. But when grip is reduced,  you can’t lean the bike far enough to use the corner knobs. Even if the tire sinks deep into the mud, there are too few knobs to really make a difference – you don’t get much extra traction. Once more, you end up with a tire that corners like a knobby on pavement, but slides like a slick tire in mud.


How can you get around this problem? On the face of it, the answer is simple: Make the knobs large enough that they don’t squirm, yet space them far enough that the mud clears from in between. The knob shape itself doesn’t make much of a difference – the engineers of several tire makers have acknowledged privately that the different knob shapes are “mostly for style.”

Coming up with the idea was easy, but the devil is always in the details. Can a knob be large enough not to squirm, yet small enough to dig into the mud? Our testing indicated that this was possible. How much open space do you need to clear mud? Fortunately, decades of racing cyclocross on various tires had given us a good idea of where to start with our testing.

How to make a knobby tire that corners predictably? You arrange the knobs so that there always is the same amount of rubber on the road, no matter how hard you lean the bike. That way, the traction is always the same, rather than suddenly breaking away as you lean and get on the edge of a line of knobs. It’s logical, and yet I haven’t seen any other knobby tire that follows that principle.


The hardest part was combining all these parameters into a single tread pattern. It took a lot of experimentation, but the result has surprised everybody. On a fast paved group ride, these tires perform as well as many racing tires. I know this sounds like hyperbole, but riders who’ve tried these tires agree. Gravel racer Ted King wrote to us: “On pavement, they’re incredibly smooth. The tread pattern is awesome  it’s really cool how deceptively simple the Steilacoom tread is, yet how well the tires work.” One independent reviewer even set Strava KOMs on his Steilacooms.


The cornering is easier to show. I can’t think of any other knobby tire that I’d dare to lean over that far on pavement. And I wasn’t even pushing the limits…


How about the performance in mud? After three seasons of cyclocross on Steilacooms, everybody agrees: They grip as well as the best cyclocross tires developed specifically for muddy courses.

Surely, there must be some drawbacks – otherwise, we should all be riding these knobbies all the time!

On the straights, the knobs have less ‘pneumatic trail,’ because there isn’t a continuous surface of rubber on the road. That means they don’t have quite the same straight-line stability as smooth-treaded tires in the same width. You may not even notice this, because the effect is small.

The knobs add a little weight, too, but once again, the effect is small, because the tread between the knobs is thinner – that part of the tire doesn’t wear, so we don’t need extra rubber there. Our knobbies weigh between 45 and 60 g more than their smooth-treaded cousins in the Rene Herse tire program. Thanks to our lightweight casings, they’re still lighter than almost any other tire with the same width.

As to the rolling resistance, the difference is so small that you won’t notice on the road even on a spirited ride with a group of well-matched friends. The biggest disadvantage may be that, like Ted King at the Epic 150, you’ll have people wonder why you ride “so much tire” on rides that include significant pavement…


I’m excited about the Rene Herse dual-purpose knobbies, because they make rides possible that were difficult to imagine before: rides that combine paved roads with muddy trails and even snow. We no longer have to choose between on-road performance and off-pavement grip. Once again, we’re pushing the limits of what our all-road bikes can do.
Our dual-purpose knobbies are available in three models:

  • 700C x 38 mm Steilacoom
  • 700C x 42 mm Hurricane Ridge
  • 650B x 42 mm Pumpkin Ridge
  • 650B x 48 mm Juniper Ridge

Photo credit: Dustin Michelson (Photo 1).

Continue Reading

Safety Advice: Non-Standard Rims and Rene Herse Tires


Safety advice: Rene Herse tires are designed for rims that meet the ETRTO standard, specifically:

  • G height: 5.2 – 6.5 mm
  • Sidewalls with hooks.

Rims that do not meet the current standards – especially hookless rims and rims with sidewalls that have G heights of less than 5.0 mm – are not recommended for use with Rene Herse tires. This is especially important when installing your tires tubeless. Our testing has found that tires mounted tubeless on hookless rims or on rims with lower-than-standard G heights have a less-than-adequate margin of safety against blow-offs. All warranties are void when Rene Herse tires are installed on rims that do not meet the current ETRTO standards.

The ETRTO (European Tire and Rim Technical Organization) sets most standards for car and bicycle tires and wheels, not just for Europe, but for the entire world. Currently, the ETRTO standards are the only standards that exist for tubeless bicycle wheels. They specify the G height of the sidewall at 5.2 mm (for tubeless) and 5.5 – 6.5 mm (for tubes, depending on the rim width). The sidewall must have a hook.

Like most tire makers, we design our tires to meet the ETRTO standards. Why don’t all rim makers follow these standards, too?

In the past, there were some poorly designed rims with overly deep wells and G heights larger than 6.5 mm. Fortunately, these rims have long been discontinued, and cyclists who still have them usually know how to deal with the problems that occur when trying to mount tires on them (as much as this is possible).

These days, we see some rims with G heights that are smaller than the ETRTO standard and no hooks. Even though these rims do not meet the current standards, this makes sense for mountain bikes with carbon rims: A tall sidewall makes the rim vulnerable if the tire bottoms out while the bike is leaning over. The tall G height provides a long lever that can crack the rim. Why hookless? Mostly because the hook is difficult to make with carbon fiber: It requires a complex 3-piece mold for the rim bed.

A ‘hookless’ rim (above) with a shorter G height is stronger and less expensive to make. Stiff mountain bike tires are inflated to ultra-low pressures. They won’t blow off their rims even if there isn’t much sidewall to hold them on. So the non-standard rims have worked fine for mountain bikes. These mountain bike rims usually come with low maximum pressure ratings.

Recently, some rim makers have introduced ‘gravel’ or ‘all-road’ rims that are made to mountain bike standards: without hooks and with low G heights. Unfortunately, these rims don’t work well for high-performance all-road tires.


We can’t say it often enough: The bikes we ride aren’t mountain bikes. They are road bikes with really wide tires. Perhaps it’s not surprising that the industry still misunderstands what gravel and all-road riding is all about: The sport has grown from the bottom up, when riders like us headed into the mountains, found new roads and designed new equipment to ride on them. Some of the established manufacturers are getting it, but many still think inside their traditional boxes of ‘Road’ and ‘Mountain’ bikes. More often than not, they’ve put our bikes into the ‘Mountain’ category.

Here at Rene Herse Cycles, we’ve always thought of them as ‘road’ bikes – that is why we coined the term ‘all-road bike’ for them. Even though my Firefly (above) has 26″ wheels, it’s not a drop-bar mountain bike. It’s a road bike with wide tires. We ride on road tires, and we need road rims for them.

That is why hookless mountain bike rims don’t work well for all-road wheels. All-road tires are supple, and they run at higher pressures than mountain bike tires. This requires an additional margin of safety.

We tested a 650B x 48 mm Switchback Hill tire on a carbon mountain bike wheel with a hookless rim and a G height 0f 5.0 mm. We mounted the tire tubeless, but without sealant (for obvious reasons). The rim is rated to 40 psi, and the tire was fine at that pressure. 40 psi isn’t a lot, even for a 48 mm-wide tire. The tire is rated to 55 psi, so we kept inflating to see what would happen. At 58 psi, the tire blew off. We then repeated the experiment with a second tire, and it blew off at 65 psi. This problem is not limited to Rene Herse tires: Other riders have reported similar blow-offs with tires from other makers.

58 psi is a lot of pressure for a 48 mm tire, but when the tolerances stack up in a bad way (slightly oversize tire and slightly undersize rim) or when the tire isn’t installed perfectly, the blow-off pressure will be lower. Then the margin of safety won’t be adequate. This is neither the tire nor the rim’s fault. It’s simply using the wrong rim for a supple all-road tire.


How much of a difference does the hook make? We put one of the tires on a HED Belgium Plus rim. The G height is the same as on the carbon rim we tested (5.0 mm), but the HED rim has a hook. Even though this is the same tire that already had blown off the rim once, it stayed on at 75 psi. The is no doubt: The hook has a crucial function in keeping the tire on the rim. Other rim and tire makers have tested and found the same: The hook significantly increases the pressure at which the tire safely stays on the rim.

Fortunately, there is another way to increase the margin of safety: Use inner tubes. We put the tire back on the hookless mountain bike wheel, this time with a tube. We inflated it to 75 psi and left it overnight. Nothing happened. We were surprised that even the violent explosion had not stretched the tire, but these beads are strong. (However, we don’t recommend re-using a tire that has blown off the rim.) That is good news: Hookless rims tend to work better when used with tubes – even though we cannot officially recommend them, since they don’t meet the ETRTO standards to which our tires are designed

Conclusion: All-road bikes are road bikes, and all-road tires are road tires: They should be mounted on road wheels. When you buy new wheels, make sure the rims are designed to the ETRTO standards, and not to mountain bike standards: You want a hook and a G height of 5.2 – 6.5 mm. If your wheels already are equipped with hookless rims, using tubes can increase your margin of safety. And check the maximum pressure ratings, not just of the tire, but also the rim: Don’t exceed them!


Tubeless is great technology – had I used inner tubes on the ride across Odarumi Pass in Japan (above), I probably would have pinch-flatted several times. But tubeless is also an emerging technology. We’ve had to learn how to mount tires (huge blasts with compressors are a sign that the rim is undersize) and how much sealant we need (more than we usually think). Now we are discovering that hookless mtb-style rims don’t work well with all-road tires.

Why do tubeless tires blow off so much more easily? Without a tube reinforcing the joint between rim and tire, it’s much easier for air pressure to force its way out. It’s still extremely rare for tires to blow off, but, with tubeless tires becoming more popular, there have been more incidents than before. They affect all brands of tires – a little while ago, a wheel maker told me of two different tires from a big German tire maker that had blown off his hookless rims that day.

Also remember that tubeless-compatible tires always need liquid sealant inside. If the sealant dries out completely, the tire can break loose from the rim sidewall and deflate suddenly. This can cause the tire to come off the rim, even if rim and tire are sized correctly.


Safety is our biggest concern, not just for our customers, but also for ourselves, because we ride our bikes hard. We’ll continue to test, and we’ll continue to work with rim makers, to drive tubeless technology forward in a safe and responsible way. The last thing we want to worry about during our adventures is whether our tires will stay on their rims! Fortunately, in almost 100,000 km (60,000 miles) on Rene Herse tires and their predecessors, I’ve not experienced a blowout. We’ll work hard to make it remain that way!

Continue Reading

Juniper Ridge 650B x 48 is here!

[youtube https://www.youtube.com/watch?v=zmt02COlmb4?rel=0&w=640&h=360]
The Juniper Ridge 650B x 48 mm dual-purpose knobbies have arrived. Unlike any other all-road tire, they combine excellent speed and cornering grip on pavement with unrivaled traction in mud and snow. At 450 g (Extralight) and 510 g (Standard), they are among the lightest tires in this popular size.
We had a lot of fun testing the new tires in the Cascade Mountains, and you’ll have a lot of fun riding them on your own adventures. We made this little video during our testing, showing the new tires in their native habitat.
The new Juniper Ridge tires are now in stock, but supplies are limited. More are on the way.
Click here for more information or to order.

Continue Reading

Ted King: Gravel Racing on Rene Herse Tires

They call Ted King the ‘King of Gravel’: Winner of both the Dirty Kanza and Grinduro in 2018, he’s the man to beat. With ‘gravel’ being the fastest-growing segment of the bicycle market, even professional teams are lining up to challenge Ted. So what does a champion do when others come after him? Ride hard and work on his equipment to ensure he has the speediest bike in the peloton. He’s also made the move to Vermont to have some of North American’s finest gravel at his doorstep.

That is how the Ted King-Rene Herse relationship came about. Ted had ridden Rene Herse/Compass tires in the past on his own road bikes, including a 700-mile self-supported trip down the California coast, and he was curious how they’d work on gravel. We sent him a few sets of tires for testing and after riding both our dual-purpose knobbies and our all-road tires in Vermont’s tough winter, he was impressed.

He loved the Steilacoom knobbies:
“On pavement, they’re incredibly smooth. There is no noticeable chatter; no abrupt transitions from mid-turn to righting the bike and pedaling straight. Segue offroad, I had all the confidence in the world when ripping gravel. The tread pattern is awesome  it’s really cool how deceptively simple the Steilacoom tread is, yet how well the tires work.”

Ted told me about the incredible James Bay Descent he and three friends were planning: A 700 km ride in northern Ontario on fatbikes in the middle of winter. It’s wonderful that even at his level, gravel riding is still about having fun on the bike first and foremost.
For a trip this remote, where even a simple saddle sore can cause real problems, I suggested he try a Gilles Berthoud saddle. His response was typical of a racer: “Changing saddles (much like changing tubeless tires) is not my favorite activity, so I will do it ASAP and report back.”
In the event, he liked the saddle so much that he got the same saddles for the entire team. During the return from their incredible ride (above), Ted wrote: “I wanted to send a note on behalf of the entire team saying that our butts are far more sore in these plush car seats than on the 40+ hours of riding. The Berthoud saddles were incredible and the entire team loved them.” And Ted asked to keep the saddle for his gravel racing rig.

Fast forward to last weekend and the first big gravel race of the season. Ted finished a close second – above he’s crossing the finish line one second behind winner Payson McElveen after they set a new course record.

Ted chose to race on our 700C x 44 mm Snoqualmie Pass tires. He texted afterward: “Everyone said that you’d need knobby tires, but the tires were perfect, because it was so dry. The Snoqualmies were amazing!” He also was very happy with the Gilles Berthoud saddle – he’s planning to keep it on his bike.
We are excited to work with a racer of Ted’s caliber. His input into tire development is extremely valuable to us. It’s great that our tires have been working so well for him, and we’ll see where our collaboration will lead us in the future.

Photo credits: Ansel Dickey (Photo 1), Ted King (Photos 2, 3, 4, 6), Land Run 100 (Photo 5).

Continue Reading

The Drawbacks of Supple Tires


At Rene Herse Cycles, we love supple tires. More than anything else, they have come to define what we do: Bring you the highest performance and greatest joy as you ride your bike. Supple casings makes tires faster and more comfortable – what is not to like?
This post’s headline already hints that, like all great things, supple tires have some drawbacks. They are high-performance parts. We make our Rene Herse / Compass tires as user-friendly as possible – for example, we add a little rubber to the center of the tread to increase their lifespan considerably. But we don’t want to reinforce our tires to the point where it compromises their performance. This means that – like all high-performance components – supple tires require a little extra care.

Tire Mounting
Supple tires are more flexible, which can make them harder to mount, especially with tubeless-compatible rims. The ‘well’ in the center of the rim is there to allow mounting and removing the tire. It reduces the diameter of the rim, and provides slack to lift the bead over the rim wall. To mount the tire, the bead must be in the well all around the rim (left bead in the drawing above).
With stiff tires, the bead is either inside the well or not. With supple tires, the bead can flex and snake in and out of the well. When that happens, the bead rests partially on the ‘shelf’ next to the well. Then the bead doesn’t have enough slack to be lifted over the rim sidewall. The tire seems incredibly hard to mount. The secret is to go around the tire several times and push the bead into the well in the center of the rim. Then, a supple tire becomes as easy to mount as a stiff one.
Pro Tip: Tubeless rim tape is thinner and slipperier than standard tape and should always be used with tubeless-compatible rims, even when you install tubes. Otherwise, the tire bead will not slide over the edge between the well and the shelf as it seats against the rim wall. Tubeless tape can be a good choice with non-tubeless rims, too, if the tire fits too tightly.

Tubeless Installation
Tubeless tires eliminate the risk of pinch flats, which can be a game changer for riding in really rough terrain. We feel this is important, so we’ve worked hard to make our wider tire models tubeless-compatible.
Tubeless installations work great for 99% of our customers, but the remaining 1% can have trouble. In rare cases, the casing can leak sealant through the sidewall. To keep the casing supple, we keep the rubber coating to a minimum. Sometimes, this can leave the casing a little porous. No problem if you are running tubes, but tubeless sealant can leak through these pores: Make sure to shake the sealant for at least 60 seconds before you inject it into the tire. For the first installation, we recommend Orange Seal, which seals the casing better than other brands. Also make sure you add enough sealant – wide tires have a large surface area and will absorb a surprising amount of sealant.
Sometimes, the tiny pores in the tire’s casing are smaller than the solids in the sealant, allowing the liquid to escape without the solids plugging these microscopic holes. You’ll see bubbles on the sidewall. (Sorry, no photo – in more than 50 tubeless installations, it has yet to happen to me.) If this happens to you, we’ll replace the tire under warranty. The alternative would be to coat all our sidewalls with more rubber, which would make our tires heavier, slower and less comfortable.

Tubeless tires can blow off the rims – independent of which brand you use. This is rarely the fault of the tire, but usually a rim problem. We’ve found that quite a few rims are slightly undersize. When you use tubes, this makes sense – a slightly undersize rim poses no problem, because the tube reinforces the joint between rim and tire. An oversize rim would make the tire difficult or impossible to mount. That is why the tolerances of rims are usually negative (smaller is OK, bigger is not). Some OEM rims appear to be intentionally undersized, to facilitate tire mounting in the big assembly plants for production bikes.
When you mount your tires tubeless, there is nothing reinforcing the joint between rim and tire. Even a slightly undersize rim can cause a tire to blow off. This problem is greater with supple tires: A stiff tire will stay on a slightly undersized rim, because its bead has to lift over the rim edge for quite some distance before it blows off. A supple tire can lift across the rim edge in just one place, because its sidewall is more flexible. This can lead to consternation among customers: “This rim worked with my last tire, and now you say it’s undersize?” What happens here is simply that the tolerances for the fit between rim and tire are tighter for a supple tire: A rim that (barely) works with stiff tires may be too far out of tolerances for a supple tire.

Fortunately, you don’t have to replace your rim just because it’s a bit undersize. Build up the rim bed with extra rim tape – use thicker ‘Gorilla Tape’ if the fit is very loose – and the tire should seat fine. You want a slightly tight fit of the tire on the rim, so you can barely mount the tire by hand, or with some light tire lever action. The tire should seat when you inflate it with a standard floor pump. If you need huge blasts of air from a compressor to seat the tire, the fit is too loose.
Don’t try to seat a tire that doesn’t fit properly on the rim! You risk having it blow off while you ride. Improve the fit by building up the rim bed with tape, then seat the tire.
Pro Tip: For many riders, it makes sense to run inner tubes. First of all, it makes your bike faster: A thin, lightweight tube adds less resistance than liquid sealant sloshing around inside your tire. The tube reinforces the rim/tire joint, greatly reducing the risk of blow-offs. If you are concerned about flats, you can add sealant to your inner tube and obtain similar puncture protection with less hassle.

Puncture Resistance
There is no doubt about it: Supple tires are less resistant to punctures – they don’t have the ultra-thick tread and reinforcing belts that resist punctures, but also make tires stiff, heavy and slow. If you get a lot of flats with your current tires – and your tires aren’t worn paper-thin – you probably shouldn’t run supple tires.
If you ride on the shoulders of busy highways, which are strewn with debris ranging from broken beer bottles to steel wires from exploded truck tires, you’ll have flats with most tires, and supple high-performance tires are definitely not a good choice. The photo above was taken during a 600 km Flèche ride. Between three bikes and one tandem, we had one puncture during the entire ride – during the 5 kilometers we rode on a highway shoulder.
Fortunately, as more riders have adopted wider tires, punctures have become a relatively rare occurrence. A 42 mm tire inflated to 35 psi (2.4 bar) will just roll over most debris that would puncture a narrower tire inflated to higher pressures. And since wider tires encourage you to explore backroads with cleaner pavement, the actual frequency of flats is much less than in the past, even though our tire casings, by themselves, are less puncture-resistant.
 
Pro Tip: Racers used to wipe their tires after riding through debris. If the debris is removed before it gets hammered into the tire, most flats can be avoided. Rather than risk injury by putting your hands on your tires, you can use tire wipers – little wires that brush debris off your tires.

Sidewall Cuts
Supple sidewalls are thinner and easier to cut. When the tire scrapes along a rock, especially a sharp one, the sidewall can get cut. How does often this happen? It depends. In some regions, the rocks are sharper than in others. Some riders let the bike move around under them more, so the tires aren’t forced into the rocks, reducing the risk of sidewall cuts. And sometimes, it is just plain bad luck.
I’ve ridden our Extralight tires over 10,000s of miles on rough gravel, and I’ve had one sidewall cut – in the epic Otaki 100 km Mountain Bike Race in Japan. It didn’t destroy the tire, as it cut only through one of the three layers of the casing. I rode the tire for another week on a tour, then replaced it.
Pro Tip: Our Standard casings use slightly thicker threads, making them more cut-resistant than the ultra-supple Extralight models.

Cost
It shouldn’t come as a surprise that supple tires are more expensive. They are made from more expensive materials. Their finer tolerances mean that they have to be made mostly by hand, by skilled labor. They are made in small batches. All that costs a little more.
Fortunately, wider tires last a lot longer, because they spread the wear over a greater rubber surface. Now that I am running 42 mm-wide tires, I find that my tires lasts about three times as long as the 28s I used to run. So even if my tires cost three times as much (and they don’t), the per-mile cost is the same.
Pro Tip: If you ride relatively few miles, your tires will deteriorate and crack before you wear them out. Keep your tires out of direct sunlight and away from refrigerators, freezers and heater blowers. Electric motors emit ozone, which destroys the rubber of your tires. Stored in a cool, dark and dry place, your tires will last (almost) forever.

In the past, supple tires were tubulars that only racers used, and only for races and special events. We all switched to our ‘training wheels’ for other rides, because the hassles and costs associated with tubulars were too great for everyday use.
Fortunately, supple tires are now available as clinchers. Wider tires have greatly improved the old problems of flat and wear resistance. We’ve made some additional tweaks to Compass / Rene Herse tires to make them more user-friendly without detracting from their performance. Our goal is to make you smile every time you go for a ride.
Further reading:

Continue Reading

How to set up tubeless tires


Tubeless tires have eliminated the risk of pinch flats. For riding in really rough terrain, they are a game changer. But like all new technologies, it’s taken some trial-and-error until we figured out how to run bicycle tires tubeless.
Of course, tubeless tires are nothing new. Car tires have been tubeless for decades, but translating that technology to much more flexible and lighter bicycle tires has not been easy. (We don’t want to ride on rubber that’s as stiff and heavy as car tires!) Modern bicycle tires fall into two groups:

  • ‘Tubeless’ tires are covered with a rubber membrane – basically an inner tube is permanently vulcanized into the tire. These tires are airtight. You can just install them, and run them without inner tubes. However, the extra rubber makes them relatively stiff and slow.
  • ‘Tubeless-compatible’ tires are not airtight, and they roll as fast as conventional tires. Their bead has been designed for tubeless installation, so you can run them tubeless – but they require sealant to make the casing air-tight and to seal the tire against the rim. The sealant also will seal small punctures that otherwise would cause a flat. Most Rene Herse tires are ‘tubeless-compatible.’

Key to mounting tubeless tires is the right technique. This is especially important with supple tires. Stiff tires mount easily – just like car tires – because their casing is so stiff that it either touches the rim walls and seals, or it doesn’t.
Supple casings make tires fast and comfortable because they flex easily. This means that they may contact the rim in a few places, and have air gaps in others – making them harder to mount and seal tubeless. They follow the general rule of high-performance components: The tolerances need to be a bit tighter, and working with them requires a little more skill.
It’s not hard to install supple tires tubeless, if you work methodically. Here is how I installed my Rene Herse Extralights tubeless while traveling in Japan, with no access to a workshop and just a few tools.

To mount a tire tubeless, here is what you need: a tubeless valve; a valve core tool; a syringe for injecting the tubeless sealant; sealant; a tire lever; an inner tube; a tubeless-compatible tire. Your rims also must be tubeless-compatible, and covered with tubeless rim tape. It’s good to have extra rim tape on hand.
You also need a pump to inflate the tire. A floor pump suffices, and in a pinch, you can get away with a frame pump. You do not need an air compressor. In fact, if you use an air compressor to make up for problems in tire/rim fit, your tire may blow off the rim later without warning.
For safe tubeless installation, a good fit between tire and rim is extremely important. Unfortunately, many OEM rims are slightly undersize, because that makes it easier to install tires in the bike assembly plants. (Imagine a rim that is slightly oversize. For a factory that needs to mount 10,000 tires a month, spending five extra minutes per tire would be a total disaster. That is why OEM rims tend to run small, and never should be larger than spec. OEM tires are installed with tubes, where a slightly undersize rim doesn’t pose a problem.)

If your tire goes on easily, the rim is undersized. Don’t try to install the tire. It may work fine at first, but it can blow off the rim without warning. If this happens in your workshop, it’s just a nuisance. If it happens on the road, the consequences can be far worse.
If your rim is undersize, it’s not the end of the world – there is a solution. Build up the rim bed with additional layers of rim tape. Some mechanics use Gorilla Tape for the extra layers – it’s a little thicker than standard tubeless tape. (Always use tubeless tape as the first layer on the rim to seal the spoke holes.) The tire should be a slightly tight fit. This makes sure that it seats correctly and doesn’t blow off the rim later.

When installing tires, make sure that the bead is in the rim well (above) all around before you lift the last part of the bead over the rim edge. The well is there to provide slack for the bead – the rim’s diameter is smaller in the center than toward the rim walls. With supple tires and tubeless rims, parts of the bead can end up on the shelf when you mount the tire. Push the bead into the rim well all around the tire – then the last bit of the bead will slip easily over the sidewall.
If you use a floor pump to seat the tire, install a tube first. This seats the beads and gives the tire its shape. Make sure both beads pop into place. Then unseat one bead (the one that popped into place first) by pushing it into the rim well, and remove the tube.

Install the tubeless valve. Don’t forget the valve nut that holds the valve in place. It pulls the valve’s rubber cone into the rim’s hole to create a tight seal. Don’t overtighten the nut: If the valve gets clogged with sealant or the tubeless setup fails, you’ll need to be able to remove the valve on the road to install a tube.

Before you inflate the tire, seat the bead as far around the rim as possible, starting at the valve.

Pull the tire upward and move the bead outward, until it sits on the shelf next to the rim wall.

Continue until the tire is too tight to pull upward. The remaining air gap is small and furthest from the valve. It will seal as the pressure pushes the tire outward.

Inflate the tire ‘dry’ without sealant at first. That way, if you need to remove the tire to add more rim tape, there won’t be messy sealant inside. Pump quickly to build up pressure faster than the air escapes.

Watch the tire as it seats. On the left, the line molded into the tire sidewall is still hidden by the rim wall. The bead hasn’t emerged from the rim’s well yet. Keep pumping until you hear a loud ‘pop’ as the tire seats.
On the right, you can see all of the line that is molded into the sidewall. Make sure it’s parallel to the rim edge all around the tire. Check this on both sides. If it’s OK, then the tire is seated on the rim.
If the tire doesn’t seat, take it off, and add more rim tape to create a tighter fit and smaller air gaps. If you use an air compressor, the tire should seat easily. If you need huge blasts of air to seat the tire, then the rim is too small. Build up the rim with extra tape, rather than risk a blow-out in the future.

Now the tire is inflated and looks great, but air will escape through small cracks and microscopic holes. To seal the tire, add sealant. Let out the air and unscrew the valve core. The beads will remain seated. (If a bead comes unseated now, it wasn’t properly seated in the first place.)

Turn the wheel so the valve is neither at the top nor at the bottom of the tire, where sealant would spray back out of the valve. Shake the sealant vigorously for a minute, so the solids are in suspension. Don’t skimp on this step! Otherwise, you’ll just inject colored water into the tire, and it won’t seal.
For our Rene Herse tires, we recommend Panaracer’s Seal Smart. It seems to seal the supple sidewalls better than other brands. When mounting the tires in the photos, I was in Japan, and Panaracer’s sealant had not yet been released. I couldn’t find our second choice, Orange Seal. So I used Stan’s. It worked fine.
Make sure to use enough sealant. Wide tires have a lot of surface area. To seal properly, you need about 90 ml (3 oz) – one to one-and-a-half of the bottles shown in the photo.

Replace the valve core. When I installed the tires tubeless in Tokyo, I didn’t have a valve core tool. A small adjustable wrench will do the job in a pinch.

Inflate the tire again. Since it’s already seated, this will be easy.

Close the valve. Now the tire looks ready to roll, but the sealant must still be distributed to seal all the microscopic gaps. Just riding the tire isn’t enough to stop all the tiny leaks.

There are different techniques for distributing the sealant. I’ve found this one to work best, because it methodically works the sealant into every part of the tire and rim interface. Make sure you have enough room. Don’t hit the ceiling, furniture, or your head. (Don’t ask how I know!)
Hold the wheel steady (left), so the sealant collects at the bottom. Quickly move the wheel upward (center). Centrifugal force will keep the sealant right under the tire tread. Hold the wheel over your head (right), still slightly tilted away from you. Now the sealant runs downward, covers the sidewall, and seeps into the gap between tire and rim.
Rotate the wheel a few degrees and repeat. (Start with the valve at the bottom, so you have a reference point.) Once you’ve worked all the way around the tire, turn the wheel around, and repeat on the other side. Now your tire is ready to ride. Riding it immediately will help distribute the sealant further.
If your tire loses air overnight, check it like a leaky inner tube. Often, you can hear and feel the air escape. Hold the tire so that gravity pulls the sealant into the leak. If it doesn’t seal, there may not be enough sealant in the tire.

Now your tubeless tire is ready to roll. Enjoy the ride!
Tubeless tips:

  • Panaracer Smart Seal works best to seal the supple casings of our Rene Herse tires.
  • Use enough sealant. When the mechanics at Paul Camp prepped bikes for their press fleet, they put 3 oz. (90 ml) in each tire, because they didn’t want trouble. More sealant makes your tires slower, but if your tire runs out of sealant, it’ll start losing air. If you want to go fast and don’t need to worry about pinch flats, use inner tubes. (Click here to read more about why tubeless tires are slower.)
  • Sealant needs to be topped up at least once a month. Supple tires push and pull slightly against the rim sidewall as the wheel rotates. If the sealant dries out, air will start leaking. Then the tire can suddenly break loose from the rim wall and lose all its air. Don’t ride your tires when there is no liquid sealant left inside – the sealant not only acts as flat protection, but it constantly seals the tire against the rim.
  • Use only new tires for tubeless installation. As a tire is ridden, the sidewalls flex and become more porous, making the tire harder to seal.
  • If you want the flat protection offered by the sealant without the hassle of tubeless installation, you can put sealant in your inner tubes. This also works best with new tires, and you obviously need tubes with removable valve cores. (The tubes we sell have removable cores.) Simply put some sealant inside the tube, and it’ll seal many punctures.
  • Most Rene Herse tires are tubeless-compatible. They are marked ‘TC’ on the tire label. The label on the package also says ‘Tubeless-Compatible.’

Click here for more information about Rene Herse tires.

Continue Reading

All-Road Bikes are the Road Bikes of the Future


All-road bikes with wide tires are the hottest trend in cycling. There is a level of excitement that we haven’t seen since the mountain bike boom of the late 1980s: These new bikes bring new people into the sport, who are enticed by the idea of cycling on small roads, away from traffic. The new bikes combine what people love about road bikes – effortless speed – and mountain bikes – go-anywhere ability – without the drawbacks. These bikes have the potential to transform the bike industry.
Like most trends, this one didn’t start within the industry. Bike manufacturers only reluctantly adopted wide tires on performance bikes. Even then, they called them ‘gravel bikes,’ in the hopes of selling one to every cyclist, in addition to the ‘road,’ ‘mountain,’ and ‘cyclocross’ bikes they already owned. But ‘gravel’ was too limiting a term for something that is much more than just a bike for the special condition of riding on gravel.
Recently, bike companies have adopted the name ‘all-road bikes,’ a term we coined way back in 2006, when we realized the potential of wide tires on performance bikes. It’s great to see cycling luminaries like Richard Bryne (founder of Speedplay) say: “The potential of this bike category cannot be underestimated.” He predicts that all-road bikes will “dwarf the previous road and MTB categories in scale and relegate them to the two margins of the market spectrum.” 
In other words: All-road bikes will becomes the go-to bike for most cyclists. Racing and mountain bikes will move to the fringes of the market, used for very specialized applications where all-road bikes reach their limits.

Bryne is not the only one to feel that way. Gerard Vroomen, the founder of Cervelo, sold his company – famous for its narrow-tire racers – to start two all-road bike ventures. Together with Andy Kessler, he started a new company, Open, and introduced the iconic U.P. (for ‘Unbeaten Path’). And he bought the former handlebar maker 3T and introduced the company’s first bike, the all-road Exploro. These bikes take the performance of modern carbon racers and add the ability to run ultra-wide tires. And both have had more influence on the bike industry than any other bike of the last decade. Vroomen’s characteristic dropped chainstay – to create room for wide tires between narrow road cranks, he moved the chainstay out of the way – has been cropping up on bikes from many mainstream manufacturers. The Open web site exclaims: “Go anywhere fast!”
We said similar things back in 2006. Our tire tests had shown that wide tires could roll as fast as narrow ones – provided they used a supple, high-performance casing. At the time, a road bike with wide tires seemed like a ludicrous idea to most. The very definition of a road bike was that it had narrow tires!
And yet, we became convinced that road cycling’s future rolled on wide tires. We coined the name ‘allroad bike’ (at first without a hyphen) to explain our vision: a new type of bike that was a road bike, but designed to go on all roads, not just smooth, paved ones.
The problem back then: There were no high-performance bikes designed for wide tires. Not even the tires themselves existed: The only wide tires on the market were heavy, stiff touring models – a far cry from the supple high-performance tires we envisioned. Our first task was to make the tires available. Then we asked the industry to build all-road bikes around the new tires.

Road Bike of the Future?
That was the title of our test of the Tournesol (above) in Bicycle Quarterly. We wrote: “Our test bike this month may well be one of the first of a new breed of ‘Allroad’ bikes: road bikes with wide tires that ride as fast as racing bikes on paved roads, and faster than cyclocross or mountain bikes on unpaved roads.”
That was in Autumn 2006. The first ‘allroad’ bike had a titanium frame, 650B wheels, and its disc brakes presaged the future. The brand itself was a short-lived collaboration between BQ reader Douglas Brooks and Seattle’s Steve Hampsten. With updated colorways and components, this 13-year-old bike could pass for a current all-road bike. Put some modern rubber on it, and its performance would be very much up-to-date, too.

And yet it’s not like we came up with something that had never existed before: We may have coined the name ‘all-road bike,’ but high-performance bikes with wide tires weren’t a new idea, even in 2006. Our research was inspired by mid-century constructeurs like René Herse – above on his amazing 7.94 kg (17.50 lb) bike during the 1938 Concours de Machines. Wide, hand-made tires; bags strapped bikepacking-style to a superlight rack; flared drop handlebars – Herse’s bike wouldn’t look out of place on a gravel adventure today.

René Herse wasn’t the first to discover wide, supple tires, either. Way back in the 1890s, bicycles became popular once pneumatic tires revolutionized their speed and comfort. The change was so profound that old bikes with narrow solid rubber tires were henceforth called ‘Boneshakers’! The whole idea behind putting air in your tires was to run wider, more supple tires. The first pneumatic tires measured about 43 mm wide – not very different from the tires many of us run on our bikes today!
So fast were the pneumatics that you couldn’t win a race without them. During the first Paris-Brest-Paris – back then still a professional race – all of the first three riders were on pneumatics, even though the technology was still brand-new! Never since has a change swept through the cycling world with such speed.

Why did tires become narrower over time? Already in the 1920s, Vélocio, the editor of the magazine Le Cycliste, joked about the ‘pneu crayon’ that most racers used: narrow, made from stiff rubber, and pumped up to the highest pressure possible. Even on the rough roads of the Tour de France (above), racers used tires that measured little more than 28 mm.
Vélocio brought back wider tires for a while, but by the 1950s, most riders were on narrow rubber again. That trend continued until recently. Why was the joy of riding on a supple cushion of air forgotten time and again?
I think the answer lies in a powerful placebo effect: Pumping up your tires harder makes your bike feel faster, even if it isn’t. Here is how it works: Your bike vibrates as your tires hit road irregularities. The faster you go, the more bumps your tires hit per second – the frequency of the vibrations increases. This experience conditions us to equate higher frequencies with more speed.
When you pump up your tires harder, the frequency of the vibrations also increases. You get the same effect as you do by going faster, except your speed is the same – but you feel faster. Conversely, a wide tire at low pressures feels slower because the vibrations that we equate with speed disappear.

In a group with well-matched riders, you realize that even though wider tires may feel slower at first, they actually aren’t. In fact, racers were among the first to put Bicycle Quarterly‘s research into practice: Soon after we showed our test results to a technical advisor who worked for several North American pro teams, the (Canadian) Cervelo team started riding on 25 mm tires. Other North American teams followed suit, and a few years later, even the European teams started to race on 25s. Now many are moving to 28s…
For racers, it’s easy to check speed. If you can hang with the group, even though you’re riding wider tires, you know that the wider tires aren’t slowing you down.

For the rest of us, the placebo of ‘high pressure = high-frequency vibrations = high speed’ can be unlearned. I no longer feel any slower on my Firefly with its 54 mm tires (above) than I do on a racing bike with 28s.

That brings us back to the original question: Are all-road bikes just a trend? Will their time come and go, like so many other bike categories that were hot for a while before the next big thing dropped? Will the joys of riding on supple, wide, high-performance tires be forgotten again?
I don’t think so. Unlike in the past, this time, the ‘wide-tire revolution’ is backed up by solid data. We won’t be tricked by placebo effects any longer! Smart people like Bryne and Vroomen are putting their money and effort into all-road bikes, because all-road bikes are transforming cycling as we know it. At Bicycle Quarterly and Compass Cycles, we are proud to have contributed at least a small part to make this happen.
More information:

Continue Reading

Bon Jon Pass Review: "An Exceptional Tyre"


“An exceptional tyre that will make you faster and happier.” That was the verdict when the British web site www.road.cc tested our Bon Jon Pass tires recently. When we hear positive feedback, whether it’s from a professional tester or a customer, it makes our day.
I smiled when I read the calculation of the weight savings. It appears that, on average, spending a British pound ($1.28) will make your bike 1.91 g lighter. Based on that metric, the tester explained that choosing “the Compass Bon Jon Pass Extralight over the Schwalbe G-One Speed was ‘worth’ £157 of savings elsewhere. Ergo, at £67 RRP, the Bon Jon Pass is a ridiculously cost-effective weight saver.” I’m not sure about the math, but it does show that lightweight tires are the easiest way to shed significant weight, especially with wide tires where the weight differences can be quite large.
More importantly, the tester liked the supple casing and the excellent grip and comfort in the real world of the Scottish Highlands: “I hardly noticed broken patches of chip seal, or small gaps and lips of manhole covers. I found myself thinking up tests for what I could and couldn’t feel through the bike’s contact points.”
Negatives? Tubeless setup with supple tires is inevitably a bit trickier – the fit between tire and rim must be ‘just right’ and the thin casing is more likely to leak air until it seals. And his riding partners apparently weren’t always happy: “I realised I wasn’t signalling road surface irregularities as much as I should be to my sub-30mm-shod brethren following behind.” Until they switch to supple, wide tires, too…
No bike test would be complete without commenting on performance – “These are fast tyres, period. World-beatingly fast.” – and price – “I believe they are worth every penny.” 
There isn’t much we can add. We developed our tires because we wanted faster and more comfortable tires for our own bikes. When others enjoy them as much as we do, it makes us happy, too.
Further information:

Continue Reading

Myth 16: Higher Tire Pressure is Faster


This used to be one of the first things you learned as a cyclist: If you want to go fast, make sure your tires are pumped up to the maximum pressure. The harder your tires are inflated, the faster they roll.

We now know that this isn’t true. The realization that tire pressure does not affect performance is the key to the revolution that has swept through the cycling world in recent years. Without this new-found knowledge, all-road bikes and their supple, wide tires would make no sense at all. Here is how it works.

Continue Reading →

Continue Reading

What Makes a Good Winter Tire?


Winter riding is fun. The crisp air, the clear skies and the beautiful views. Getting out and breathing fresh air. There are many reasons to enjoy it.
Winter riding requires preparation. The most obvious is clothing – which we’ll leave for another post. Today, let’s talk about what makes a good winter tire.

Cold temperatures make rubber less grippy. There is no way around this. In theory, it should be possible to formulate rubber compounds specially for optimum grip in cold conditions. In practice, many ‘Winter Compound’ bicycle tires offer less grip in cold conditions, rather than more.
With all tires, you need to consider the reduced grip when it’s cold. Especially on familiar routes, it can come as a surprise when the grip suddenly bleeds away, at speeds that are well within the limits when the temperatures are warmer.

Having ridden many tires in cold conditions, I can say with confidence that the rubber compound of our Compass tires is among the most grippy you’ll find anywhere, cold or warm, wet or dry.

The chevron tread of Compass road tires helps to improve traction by interlocking with the road surface – which works regardless of the temperature. Even so, take it easy during cold days!

What about snow? Snow is surprisingly grippy. How much tread you need depends on the temperature: Cold snow requires only a chevron tread, like that of our road tires, to hook up. (You’ll see an imprint of the tire tread on the snow surface.) But when the temperatures are around freezing, the slushy snow is slippery, and you really need knobs to get good grip. (The knobs don’t hurt when it’s colder, either.)
Should a snow tire be wide – to float over the snowpack? Or narrow – to cut through the snow and try to find grip on the ground underneath?

Rally cars use narrow tires in snow. They are heavy and powerful, which allows their tires to dig down to a firm surface underneath the snow.

Snow cats use the opposite approach: Their wide tracks allow them to travel on top of deep snow without sinking in.

For bicycles, wide tires seem to be a better choice. Compressing the snow takes energy, and the less you sink in, the easier you roll. And cyclists don’t have enough weight and power to dig through the snow into the firm ground below.
What about ice? Under most conditions, only studded tires grip on ice. They punch holes into the ice that allows them to interlock with the surface. However, studded tires aren’t much fun to ride on dry roads. I suspect that a supple tire with studs wouldn’t work well – you probably need a stiff tire to push the studs into the (hard) ice.
There is one other issue: When it snows, many communities spread fine aggregate on the roads for better traction. Often, that aggregate contains freshly crushed rocks that can be very sharp and cause flat tires. In our area, we’ve found that the crushed rock will puncture worn tires – probably both because they are thinner and because aged rubber is easier to cut. Running relatively new tires has eliminated that concern for us.

If you live in a place that sees snow, but also dry roads, our dual-purpose knobbies are hard to beat as all-round winter tires. They roll as fast on dry roads as most racing tires. They corner as well as most road tires (above). And yet on mud and snow, they offer the grip of the best knobbies. Available in 700C x 38 and 650B x 42 mm, they are a great choice for rides where you may encounter all kinds of conditions.
Click here for more information about our tires.

Continue Reading

Tire Fit Gauge


How wide a tire can I fit on my bike? It’s a common question, and yet it’s difficult to figure out, especially when you plan to change wheel sizes.

Hahn Rossman has developed a simple tire fit gauge that allows checking tire clearances on your bike. Put the disc for the tire width in the slot for the wheel size. Place the gauge on a dummy axle (any old hub axle will work). Rotate the gauge around the axle to check clearances between the chainstays, at the back of the seat tube and between the seatstays.

It’s such a simple tool that you wonder why nobody else has made one before. Above, you can see that if your frame has clearance for 700C x 23 mm tires…

… you may also be able to fit 650B x 38 mm tires…

… but you need a lot of extra clearance to fit 26″ x 54 mm tires.
The outer diameter of all wheels is the same, but it’s the clearance to the chainstays that is often too tight. The gauge makes it easy to visualize where the widest portion of the tire will be. It eliminates the guesswork that can make conversions to different tire sizes a hit-or-miss.
The Tire Fit Gauge is laser-cut from plexiglass. It’s in stock now. Click here for more information.

Continue Reading

Why Supple Tires Run at Higher Pressures


One of the benefits of wide tires is that they run at lower pressures. Yet the supple casings of our Rene Herse tires require higher pressure to corner well and not bottom out on big bumps. Doesn’t the higher pressure negate the benefits of wider tires?

Think of the tire casing and the air inside as two separate springs. Let’s call them the rubber spring and the air spring. Both work together to support the weight of the rider. How you distribute the load between the two springs changes with a supple tire: Less rubber requires more air. And vice versa.

When you inflate your tire, you are aiming for a tire drop of about 15-20%. (Tire drop is how much the tire deforms under the rider’s weight.) Whether you use rubber or air as the spring doesn’t change how much the tire deflects. What changes is how the tire behaves as it flexes.


On tires with stiff casings, you use rubber as your suspension, and you need little air. The extreme are airless tires like those found on dock-less bikeshares. They use only rubber and foam to support the bike and rider. However, rubber has a lot of hysteresis, so it consumes a lot of energy as it flexes. That is why stiff tires are slow.

A tire with a supple casing (above) relies mostly on air to support the weight of bike and rider. Air has almost no hysteresis: Little energy is lost as the tire flexes. That is part of the secret behind the speed of supple tires.


A supple tire is more comfortable, too. The thinner casing has less inertia and requires less energy to flex, so it can react more quickly to surface irregularities. A supple tire absorbs the vibrations, while a stiff tire transmits them to the bike and rider. And since vibrations slow you down, that makes the supple tire faster, too.

So you gain speed twice: the thinner casing absorbs less energy (smaller hysteretic losses) and it transmits fewer vibrations (smaller suspension losses). Talk about a win-win situation!


It’s important to remember that supple tires need more air to hold up your bike. After all, you’ve reduced the spring rate (stiffness) of the rubber spring, and you need to make up for this by increasing the spring rate of the air spring. If you run your supple tires at the same pressure as stiffer ones, you risk having the sidewalls collapse during hard cornering. And that can be dangerous.

Put in a little more air, and you’ll find that supple tires offer more grip than stiff ones: The supple casing reacts better to surface irregularities and thus keeps the tire in better contact with the road.


There is no need to go back to the days when we inflated our tires to the maximum indicated on the sidewall. Use Bicycle Quarterly’s tire pressure chart (above) as a starting point, and experiment from there.

Remember that the chart lists the weight per wheel, not for the entire bike. I apologize that the chart stops at 37 mm – when Frank Berto measured the tire drop of dozens of tires, 37 mm was the widest road tire he could find!


On gravel and in mud, there is less traction, and thus the forces on the tire are lower. The tires won’t collapse even if you run very low pressures. On soft surfaces, you get more traction, more comfort and more speed at those low pressures.

Generally, I run about 10-20% less air in my tires on gravel than I do on pavement. You don’t want to run a pressure that is too low – it flexes the tire sidewalls excessively, which robs power and ultimately breaks the fine threads that make up the casing. And of course, you don’t want to bottom out except on rare occasions, even when running tubeless tires.

Finding the right tire pressure takes some experimenting. If the tire feels too stiff, let out some air. If you feel the tire folding under the rim as you corner, add some pressure. Also remember that the gauges on bicycle floor pumps are notoriously inaccurate, so if you pump up your tires to the pressures from the chart and your bike doesn’t feel right, trust your feel rather than your gauge.

Conclusion: Even though supple tires run at higher pressures, they are faster, more comfortable and grip better than tires with stiff casings. The ‘correct’ tire pressure should have some margin of safety above the point where the tire collapses during hard cornering.

Continue Reading

Why We Don't Do OEM


Wouldn’t it be awesome if you could buy a complete bike that is already equipped with Compass tires? Take a bike like the Masi Speciale Randonneur (above), roll out of the bike shop and into the hills, your tires gently humming as they roll over the rough pavement. When the road turns to gravel, the feel of the bike changes on the loose surface, but its speed and comfort remain the same.
We get a fair number of requests from bike manufacturers who want to install Compass tires as OEM (Original Equipment Manufacturer) parts. It seems like an opportunity for Compass: Once riders have experienced the joys of riding on supple tires, they won’t return to stiffer, harsher, slower tires. So why don’t we do OEM sales?

The answer is simple: Cost. Compass tires use the highest-grade materials, from the fabric for the casing to the rubber for the tread. They are made by hand, which requires skilled, experienced labor. Compass tires are made in Japan, a country with high wages. All these factors increase our production costs.
At the consumer level, we (and other small makers of bicycle components) can compensate for the high cost with our low overhead. Big companies need a lot of money for administration, marketing, shareholder profits, etc. We eliminate most of those, and the final consumer price of a Compass tire isn’t much higher than that of a mass-produced tire.

OEM prices are low because the orders are large, and even big companies can significantly reduce their overhead. For small companies like Compass, there isn’t much overhead, and to compete at the OEM level, we’d have to reduce our production costs. We’d have to downgrade our specifications and move production to a low-wage country. That direction isn’t really where we want to take Compass Cycles.

Others have taken our ideas and made them ‘OEM-comptabile.’ At Compass Cycles, we welcome that bike makers now can spec affordable bikes with wide allroad tires. Bikes like the Surly Midnight Special (above) simply wouldn’t exist if there were no affordable OEM tires to ship them with from the factory. Similarly, Masi’s Kellen LeBlanc explained that their Speciale Randonneur was delayed for years until a lower-priced, wide 650B tire became available.
Now more and more cyclists experience the joys of all-road riding on wide rubber. In the past, we never saw another bike on our favorite routes in the Cascade foothills. Now we meet cyclists on almost every ride. Their smiles tell it all.
And in the future, our Compass tires (and other components) provide great upgrades that will make them fall in love with their bikes all over again.
More information:

Continue Reading

New Products and Back in Stock


We are excited about a number of new products. MKS has reworked their popular Sylvan pedals with silky smooth cartridge bearings. Now called the Sylvan Next, we’ve carried the Touring version for a while. New in the program is the Track pedal (above).
The new Track pedals are a great choice not just for track riders, but for all riding with cycling shoes and toeclips. The cut-away pedal body provides better cornering clearance and reduces the weight, while still offering full support for the shoe. Eddy Merckx used to race on track pedals because of these advantages.

What is the difference to the Touring version (above)? The platform of the Touring pedal is wider, so giving you the option of riding comfortably in street shoes, too. And since it’s double-sided, you can use it with or without toeclips. The Track pedal is easier to use with toeclips, since the flip tab at the bottom helps with rotating the pedal to insert your foot into the toeclip.

Both pedals are available in ‘EZY Superior’ Rinko versions, which allow removing the pedals in seconds without tools – great for travel bikes and for cyclists who ride one bike with multiple pedal systems. Removing the pedal couldn’t be simpler: Turn the ring on the adapter, push it inward, and the pedal releases.

Our Compass Switchback Hill 650B x 48 mm tires have been very popular, but until now, there were no fenders to go with them. We asked Honjo to custom-make their smooth 62 mm-wide fenders in a new XL version for us. With a larger radius, these fit perfectly over ultra-wide 650B tires (up to 50 mm wide).
To provide clearance for the chain with road cranks, fenders cannot get wider than this, so this fender does not wrap quite as far around the tire as our fenders for narrower tires. It still provides better spray protection and more tire clearance than any other fender we’ve tried.

Pacenti’s Brevet has become our most popular rim: strong, reasonably light and without the cracking problems that bedeviled many recent rims, it’s proven reliable and easy to build. It’s also tubeless compatible. We are excited to offer this excellent rim in new 700C versions, as well as the well-known 650B.

The HED Belgium Plus is one of the best modern 650B rims out there. It builds straight and the diameter is spot-on, making tubeless installations a snap. We’ve persuaded HED to keep it in production, and the rim-brake version now is back in stock. Disc brake rims will arrive soon.

Gilles Berthoud’s underseat bag is a great way to add carrying capacity to a bike that doesn’t have provisions for luggage. It holds a rain jacket, arm warmers, a wallet and some food in addition to spare tubes and tire levers. It’s made from the same waterproof cotton with leather edging as Berthoud’s famous handlebar bags that last (almost) forever.
We now carry these bags with a more secure leather buckle closure. The previous elastic has worked great for me, but since you won’t access a saddlebag while riding, the two-handed operation is no problem, and you no longer run the (admittedly small) risk that the elastic breaks, spilling the contents of the bag onto the road.

The Berthoud saddle bag attaches either with straps to the rails of your saddle, or with a KlickFix adapter directly to most Gilles Berthoud saddles (above).

Our handlebars combine modern materials with classic ergonomics. Their generous shapes provide room to roam during long days in the saddle. Now all sizes are back in stock.

The Compass taillight has been very popular. It combines a beautiful shape with modern electronics: a powerful LED and a standlight circuit so you remain visible when you stop. It incorporates a reflector. Mounted between the seatstays, it’s visible from where it matters, yet it’s well protected. Our taillights are made by a good friend right here in the U.S., and we’ve had a hard time making enough to keep up with demand. Now they’re back in stock.
Click on the images above for more information, or click here to check out the complete Compass Cycles program.

Continue Reading

How Wide is Right for Me?

open_corner
Our ideas of what is a performance bike have changed a lot in recent years! One of the most exciting bikes of the moment is the Open U.P. – a carbon race bike that accepts 50 mm-wide tires!
Not too long ago, every performance road bike had 700C x 23 mm tires. Now you have to choose not just how wide you want your tires to be, but – thanks to disc brakes – even which wheel size you want to use! For the Bicycle Quarterly test, we rode the Open with 650B x 48 mm tires, but our second tester, Nate King, raced his Open with 700C x 44 mm tires. Which is better? Or should you get several wheelsets for different courses? Is there a reason to switch tires and wheels on the same bike?
tire_test
Let’s first talk about some fundamentals: Wider tires don’t roll slower than narrow ones. Bicycle Quarterly‘s latest tire tests, published in the Winter 2016 issue (BQ 58), have shown this once again: In a real-road scenario, even 54 mm tires don’t roll slower than 32 mm – or any size in between. Before this, we already tested tires between 20 and 32 mm tires and found that the 20 mm and 23 mm were slowest, and all the others offered the same performance.
By the way, we tested at 22 mph, so this factors in the greater air resistance of the wider tires. It appears that wider tires have slightly lower rolling resistance, which cancels out the small increase in wind resistance. This means that at lower speeds, wider tires probably are faster than narrower ones. We tested on very smooth asphalt. On rougher roads, wider tires also are faster.
Yes, I know it’s not what we used to believe – we were quite surprised when we saw the results of our testing, but we’ve confirmed this time and again. And so have others in recent years.
To summarize all this research: Narrow tires (<25 mm) are slow. Above 25 mm, the width of your tires are won’t change your speed (at least up to 54 mm wide tires).

That doesn’t mean you can just slap any wide tires on your bike and expect it to go fast. What will change your speed is how supple your tires are: Tires with high-performance casings are faster, more comfortable and offer better traction, regardless of their width. If you choose heavy, reinforced ‘touring’ models when you switch to wider tires, you’ll likely to be disappointed – they’ll roll slower than racing tires because of their sturdy casings, not because of the extra width.
So we know that supple casings are key, and that width doesn’t matter. What size tires should we run then? Is wider always better? And what about wheel size?
open_paved_corner
Wider tires offer more cornering grip. This is true for racing cars and motorbikes as well as bicycles. On bicycles, there are two reasons for this: More rubber on the road gives you more traction. And wider tires are inflated to lower pressures, which means that they stay in contact with the road. If your tires don’t bounce over small irregularities in the pavement, they have even more traction than their width alone would suggest.
If you like to corner fast, you want the widest tires possible. Even on smooth pavement, the difference between 38 mm and 48 mm-wide tires is noticeable, and on rough surfaces or even gravel, it’s no contest.
WheelTest
Wheel size is another important consideration. The photo above shows three Bicycle Quarterly test bikes with identical geometries (head angle, trail, BB height, etc.), but different wheel sizes. What we found in that test: Wheel size greatly influence the handling of your bike. Larger wheels make the bike more stable, and so do heavier wheels – it’s the rotational inertia that matters, not the outer diameter.
Since wider tires are (slightly) heavier, you’ll want to decrease the wheel size to keep the rotational inertia – and thus the handling – the same. That means that your wheel size should be chosen based on your tire width and tire weight. That way, you can enjoy the nimble handling of a great racing bike even with wide tires.
Let’s a look at a few tire sizes that I enjoy riding, with their pluses and minuses:
ritchey_swissx
38 mm wide

  • To me, tires narrower than 38 mm don’t really make sense any longer. 38 mm tires still give you the “connected to the pavement” sensation that makes a racing bike feel so fast. Below 38 mm, all you gain is harshness. The bike doesn’t feel any better, just more jiggly.
  • 38 mm tires are great for pavement and occasional gravel riding.
  • To go with 38 mm tires, you have a choice of wheel sizes:
  • If you like the nimble handling of a racing bike, then choose 650B wheels for 38 mm tires.
  • If you prefer a bike that locks onto a cornering radius and won’t be deflected even if tense up in mid-corner, then use 700C wheels for 38 mm-wide tires.

hahn_shiretoko
42 – 44 mm wide

  • Adding 4 mm to the width of your tires gives you some added plushness – compared to 38 mm, you’ve increased the air volume by 22%.
  • In exchange for that added cush, you lose a little bit of connection to the road. To me, that isn’t a big loss, and I enjoy the greater traction and go-almost-anywhere capabilities of the wider tires.
  • For tires this wide, 650B is the optimal wheel size.
  • 42-44 mm tires are fine for most gravel riding. They have the advantage that good rim brakes (like our Compass centerpulls) fit over them – even with fenders. In fact, fender mounting becomes a compromise with tires wider than 44 mm (see below).

gravel_hairpin
48 – 54 mm wide

  • Now we are getting into some seriously wide tires for a road bike! A 54 mm tire holds twice as much air as a 38 mm tire.
  • Tires this wide change their feel depending on the pressure you run:
    • With the tires inflated to 38 psi (2.6 bar), our Open U.P. test bike felt like a road bike. The tires made more noise as they rolled over the pavement, but otherwise, the feel wasn’t all that different from narrower tires.
    • Letting out some air and reducing the pressure to 26 psi (1.8 bar) changed the bike completely. Now it was super-plush. The tires still had enough air so they wouldn’t collapse under hard cornering, but I could feel the ‘suspension’ when riding out of the saddle. At this pressure, the tires were ideal for rough gravel.
  • For tires this wide, I definitely recommend 650B wheels. With 700C rims, your bike will just plow straight ahead like a 29er mountain bike, and you’ll need suspension to absorb the bumps that you cannot steer around. On my Firefly (above), I went with 26″ wheels for a more agile handling. As a result, the bike feels remarkably similar to a good racing bike.
  • Fender mounting is an issue with tires this wide and road cranks: Ideally, a fender should be about 20 mm wider than the tire, but the chain will hit a fender that is wider than 62 mm when riding in the smallest gear! The solution is using a 62 mm fender that doesn’t wrap around the wheel very much and mount it a bit higher above the tire. It works, and we now offer a 650B fender specifically for 47-48 mm wide tires.

otaki_07
How about tires wider than 54 mm? That might be interesting, but you can’t really fit them between road cranks with narrow Q factor. 54 mm tires already are quite wide: They have the same air volume as 2.3″ mountain bike tires – it’s just that they don’t have knobs on the shoulders, so they measure out a bit narrower. Below is a comparison of the air volume of my three favorite tire sizes (to scale).
38-54-mm-tires
To summarize, if you want your bike to feel connected to the pavement like a good road bike, I recommend 650B x 38 mm tires. Compared to narrower tires, you get added comfort and speed on rough pavement, and more cornering traction, too.
I prefer a little extra rough-road performance and even better cornering traction, so for paved rides, my choice is 650B x 42 mm. You lose a little of the connection to the road, but during hard cornering, you actually get more, not less, feedback of how much traction you have in reserve, because the tires can really key into the pavement.
If my ride includes a lot of gravel, I’ll pick 650B x 48 mm or even 26″ x 54 mm. On pavement, the downside is that you get some tire roar – how much depends on the diameter of your bike’s frame tubes that provide the resonance chamber for the noise – and the tires’ feel is more sensitive to tire pressure. On the plus side, the traction in paved corners will blow your mind.

If you are using lightweight carbon rims and superlight tires, like our Compass Extralights, then it makes sense to go up one wheel size to compensate for the lighter weight. So for 38 – 43 mm tires, I’d recommend 700C wheels, and 44+ mm tires, I’d use 650B. Otherwise, your bike gets that ‘small-wheeled’ feel: The bike doesn’t hold its line on its own, but requires active input from the rider to go straight. It’s not a big deal, but we are talking about optimizing your bike here.

It seems that more and more riders are converging on these tire sizes: BQ‘s second tester for the Open U.P. recently received the latest model from his sponsors (above), and he spec’d it with 650B x 48 mm tires – like our test bike. And he tells us that he loves it!
With these suggestions as a starting point, I recommend test-riding a few bikes with different wheels and choosing the ones you like best.
Resources:

Photo credits: Toru Kanazaki (Photo 8), Natsuko Hirose (Photos 1, 3), Nate King (10).

Continue Reading

Road.cc Reviews the Compass Switchback Hill


Road.cc tested another Compass tire. After the Barlow Pass and the Steilacoom dual-purpose knobbies, they had a go with the Switchback Hill 650B x 48 Extralights. This time, they used a different tester, Dave Atkinson. He liked the tires just as much…
His conclusion echoes ours: “At a time when people are doing roll-down tests to see if it’s worth switching to 28mm tyres from 25s, my advice would be to skip a few sizes and fit a pair of these, if you can. They’re great.”
I smiled when I read that in group rides, he had “to remember to point out holes and other imperfections that you can glide over on 48s but might easily pinch-flat a 25.” I remember that from the days before my friends switched to wider tires, too…
His conclusion: “There really is no downside to a big tyre like this.” But rather than retell his story, just read his review for yourself!

Continue Reading

Supple Trumps Wide

hahn_popocatepetlHigh-performance bicycles have changed tremendously in recent years. As one manufacturer said at last year’s Interbike: “In the past, everybody asked how much your bike weighed. Now all they want to know is how wide a tire it fits.”
Wide tires have revolutionized how we view performance bikes. In the past, you knew a rider was serious about going fast if his or her tires were narrow. Now it’s almost the opposite: The latest performance bikes have wider tires than many utility bikes (below).
utility_vs_enduro_allroad
This change has happened so quickly that the bike industry can hardly keep up. Just a few years ago, ‘gravel’ bikes had clearance for 32 mm tires. Now 48 mm tires are becoming the standard for ‘allroad’ bikes that are intended as much for pavement as for gravel.
As a result of this rapid change, many cyclists are on the fence when it comes to buying a new bike: Bicycle technology seems so much in flux right now that it seems prudent to wait and see how it all shakes out. Why not postpone a new bike purchase for a few years? By then, we should know exactly what a 21st century high-performance bike looks like.
jan_herse_gravel
Or should you just take the plunge and buy the bike of your dreams? After all, there is so much fun to be had. Will a 2018 bike be obsolete in just a few year’s time?
It’s difficult to predict the future, but what I can say is this: The bikes we enjoy most haven’t changed in the last decade. My René Herse (above) is seven years old, and yet, the only thing I’d do differently today is add low-rider racks and make it Rinko-compatible. The basic idea of what makes a great bike for paved and gravel roads hasn’t changed – it’s just that the mainstream bike industry has taken some time to catch up.

 
In practical terms, for normal road riding, 38-42 mm tires will serve you well. If you intend to ride mostly on gravel, look for clearances that allow 48-54 mm tires. It’s unlikely that these recommendations will change much in the future. Wider tires are almost impossible to fit without giving up the character and feel of a road bike: narrow Q factor, nimble handling, and light weight.

 
What if you aren’t ready to take the plunge? Fortunately, you don’t need a new bike to transform your riding. The science is undisputed: The benefits of the ‘wide tire revolution’ lie mostly in the supple casings. The extra width is just an added benefit.

In other words: A supple 28 mm tire will be faster and more comfortable than a 48 mm-wide ‘touring’ tire with a stiff casing. Especially if you ride mostly on pavement, you can experience 80% of the benefits simply by switching to supple high-performance tires in a size that fits your current bike.
diverge_blog
You’ll be amazed by the transformation. Our Specialized Diverge long-term test bike could handle only 32 mm-wide tires (with fenders). That didn’t lessen the fun when I took it on wonderful adventures, like the ride up the abandoned road to Carbon Glacier on Mount Rainier (above).

I also enjoyed its speed and grip on smoother roads. Simply switching your tires buys you time while you decide what you want in your next bike. Only caveat: After riding supple high-performance tires, there is no going back. Once you’ve tried them, you’ll choose great tires for your next bike, too, no matter their width.
More information:

  • Compass tires in widths between 26 and 55 mm (26″, 650B, 700C)
  • Bicycle Quarterly 58 with our latest tire tests, which compare the performance of tires between 32 and 55 mm wide.
Continue Reading

A knobby faster than most road tires?


At Compass, we see little point in replicating what you already can buy from others. When we made our first knobby tires, we wanted true dual-purpose tires. Could the new knobbies match the on-pavement of good road tires, yet grip as well in mud as true cyclocross tires. Impossible? You’ll never find out unless you try…

After a few seasons of cyclocross, there is no doubt that the Compass Steilacoom (700C x 38 mm) and Pumpkin Ridge (650B x 42 mm) offer plenty of grip and shed mud well – as you’d expect from their widely spaced knobs.
How about their on-pavement performance? I’ll let others speak on that. Matt Surch, the well-known Canadian gravel racer, wrote: “I don’t understand how the tread rolls so fast and quiet… these are wild!”

When BQ tester Mark tried them, he wrote: “Once the wind drowned out the tire roar at high speed, I was thinking about how unremarkable the Steilacoom tires had rolled on the paved descent. I had pretty much forgotten that I was riding on knobbies.” Yet he was glad to have them when a road closure detoured us via a muddy trail (above).

And now Mike Stead tested a set of Steilacooms for www.road.cc. Among other adventures, he set two Strava records on these tires. One was for a gravel descent. His comment: “I wasn’t even pushing that hard. […] The Steilacooms make you a better, faster descender than you deserve to be.”
The second KOM surprised not just him, but us as well: He set a new record for a flat-out 60-second sprint – on pavement. He wrote: “Averaging 45 kph, the Steilacooms made an awesome high-pitched noise as I fanged along the straight. Just to prove it wasn’t a fluke, I went back the next week and recorded exactly the same time to the second.”
Mike’s time on the Steilacooms was two seconds faster than the previous KOM record, which he had set on our Barlow Pass tires. Does that mean our knobbies are faster than our road tires? Not necessarily – there are too many variables – but it shows that they certainly aren’t much slower. And that is remarkable, considering that our road tires are among the fastest in the world.

In a future post, I’ll explain how we created a knobby that doesn’t ride like a knobby… until you hit mud or snow, when it behaves exactly like a knobby. But don’t take our word for it – read Mike Stead’s review.

Continue Reading

Compass Antelope Hill 700C x 55 mm Tires


We are proud to introduce our biggest tire yet, the much-anticipated 700C x 55 mm Antelope Hill. The new tires have arrived with the latest shipment and are now in stock.
Antelope Hill is the unofficial name of the last great climb of the iconic Oregon Outback, the 360-mile gravel race that traversed Oregon from the south to the north. Like many gravel rides, almost a third of the Outback route is on pavement, including Switchback Hill itself (above). The ideal tire for this and similar rides combines excellent speed on pavement with enough width to float on top of the gravel, rather than sink into the loose aggregate.

The new 700C Antelope Hill completes the trilogy of ultra-wide Compass allroad tires, which also includes the 650B Switchback Hill – named after the first big climb of the Oregon Outback – and the 26″ Rat Trap Pass.
Like most Compass tires, the Antelope Hill is available with our Standard casing and tan sidewalls (above). This is the more economical choice. Also, the sidewall is stronger to resist cuts better.
For the ultimate in performance, we recommend our Extralight casing, available in tan or black. This is the same ultra-supple casing found on top-level tubular tires. The Extralight isn’t just incredibly light for such a big tire (465 g) – the supple casing also improves its speed and comfort further. And thanks to the extra width and hence lower pressure, the Antelope Hill Extralights are strong enough even in rough terrain.
Experienced riders can use these tires on rough trails, but they are not intended as true mountain bike tires. The supple sidewalls aren’t stiff enough to climb out of ruts, and the casing can suffer cuts if it’s forced into sharp rocks. We mostly intend them for riders who enjoy their 29er mountain bikes on gravel and paved roads. Under those conditions, Compass allroad tires will transform your bike’s performance. You’ll want to ride it everywhere… We can’t wait to see where people are taking their Antelope Hills!
The Antelope Hills are available now. For more information or to order a set, click here.

Continue Reading

How to Test Tire Performance


In the 15 years of Bicycle Quarterly, one of our discoveries has been that testing bicycle performance isn’t easy, and that taking shortcuts often has led to erroneous conclusions.
Carefully designed tests that replicate what happens when real cyclists ride on real roads have allowed Bicycle Quarterly to debunk several myths. Certainly, the biggest change in our understanding of bicycles has been about tires.
Tires, more than anything else, change the performance, feel and comfort of your bike. We now know that fast tires can increase your on-the-road speed by 10% or more. But how do we know which tires are fast?
vittoria-corsa-speed-2016-1
Lab testing is the most common way to test tire performance, usually on a steel drum (above). In the past, these steel drums were smooth. Now the testers have added some texture to simulate the roughness of the road surface. Unfortunately, that doesn’t address the fundamental flaws of drum testing:
1. The curved drum pushes deep into the tire

Since the drum is convex, it pushes deep into the tire, unlike a real road, which is flat. The more supple the tire, the deeper the drum pushes. This makes the tire flex more, which absorbs more energy. That is why a stiff tire performs well on the drum, and a supple tire does not. We know that the opposite is the case on real roads.
rolling_resistance_pressure
Increasing the tire pressure also makes the tire harder, and so the drum won’t push as far into the tire. That is one reason why drum tests show higher pressures rolling much faster (above). According to this data, increasing your tire pressure from 60 to 120 psi (4.1 to 8.3 bar) reduces the resistance by 30%!

Bicycle Quarterly‘s real-road testing (above) has shown that the opposite is true, especially for supple tires: They roll slower at 100-120 psi than at lower pressures. (Higher power = slower.)

This problem with drum tests has been recognized for a long time. There is a way around this problem, but it’s very expensive: Make the drum so large that it’s barely convex. One of the best drum testing rigs is in Japan, and from what I’ve heard, it measures about 7 feet in diameter. That means it’ll push into the tire much less, and thus it won’t make stiff tires seem faster than they really are.
On the other end of the spectrum, you have efforts to measure tire performance on small-diameter rollers,  like those used for training. That will always be futile: Anybody who has ridden on rollers knows how high the resistance is, because the rollers push so deep into the tires. And if you want to increase the resistance further, you just let some air out of the tires…
Not surprisingly, tests on small-diameter rollers show the ultra-supple Compass ‘Extralight’ casing rolling not much faster than the ‘Standard’ version. On real roads, the performance difference between the two is quite noticeable.

TOUR magazine in Germany has designed a test rig that eliminates the problems associated with the convex drums: Two wheels carry weights that are off-center, so they rock the wheels like a pendulum. This test rig rolls back and forth on a flat surface. You could even use it to test on real roads. The longer the test rig rocks from side to side, the lower the tires’ rolling resistance.

This test showed the Compass Bon Jon Pass as the fourth-fastest tire they’ve ever tested. (‘Rollwiderstand’ means ‘rolling resistance;’ the dark bars are for ‘rough asphalt;’ the light ones for ‘smooth asphalt;’ to convert the pressure from bar to psi, multiply by 14.5)
It’s interesting to compare the same tires – Compass Bon Jon Pass 700C x 35 mm tires (standard casing) vs. Continental 4000 S II in two tests:

  • www.bicyclerollingresistance.com tested on a steel drum:
    • Compass (6 bar / 90 psi): 15.8 W
    • Continental (7 bar / 100 psi): 12.9 W
    • Conti has 18% lower rolling resistance.
  • TOUR magazine used their rocking test rig:
    • Compass: 17 W
    • Continental: 17.5 W
    • Conti has 3% higher rolling resistance.
    • Compass is fourth-fastest of all tires TOUR tested (graphic above).

It’s clear that the drum test disadvantages a supple tire – the stiffer Conti performs much better. Adding to the confusion, www.bicyclerollingresistance.com gets lower resistance values than TOUR – it should be the other way around with the drum pushing into the tire.
There is another odd thing: TOUR shows the wider Compass tire in 4th place on the smooth road surface, but in 5th place on the rough surface, where it gets beaten by the narrower Conti rolling at higher pressure. That isn’t how it works in the real world, where the advantages of wider tires and lower pressures are greatest on rougher roads. That brings us to the second problem of these lab tests:
2. No rider on the bike
rumble_smooth
Without a rider, you have no significant suspension losses. Suspension losses are the energy that is absorbed when vibrations cause friction between the tissues of the rider’s body. Without a rider, there is nowhere to absorb the energy – steel weights don’t behave like human tissue.
Without suspension losses:

  • vibrations wouldn’t slow you down.
  • wider tires would be slower than narrow ones.
  • higher tire pressure would make your bike faster.

On the road, with a rider on board, all these statements are false – because suspension losses absorb energy, and reducing suspension losses is key to making a bike go faster. Understanding suspension losses has revolutionized our understanding of tire performance. It’s the underpinning of the ‘wide tire revolution.’

The lab tests described above are like a return to the last century, when we all ‘knew’ that narrow tires rolled faster because they could run at higher pressures. So we ran 19 mm tires (above) and inflated them rock-hard for optimum performance. That was long ago – when did you last see a short-reach racing brake with so much tire clearance?
Today, even professional racers run 25 mm tire at 80 psi. They have found that this is faster, no matter what the steel drum tests say. Racers have concluded: When tests don’t replicate the real world, they aren’t of much use.
At least TOUR‘s test rig gives us some indication about the energy absorption in the casing. It neglects one half of the equation – the suspension losses – but it’s useful if we understand its limitations. On the other hand, tests on small-diameter drums are just misleading – because if you design a tire to perform well in these drum tests, it’ll have a stiff casing and ultra-high pressures. And that means it won’t perform well on real roads.
A better lab test?

Is there a way to design a realistic lab test for tire performance? After all, Bicycle Quarterly‘s test procedures – testing only on totally calm days; when temperatures are constant; with a rider who has trained to keep the same position for lap after lap – are fine if you are doing scientific research. But they are not feasible for commercial applications, where you need to be able to just mount a tire on a wheel, take it to the lab, and get an immediate reading of its performance – without having to wait until the weather is right, the wind has died down, and the temperature is constant.
At Bicycle Quarterly, we’ve been thinking about this. Current drum tests load the tire with metal weights that don’t absorb much energy as they vibrate. Is there another material that behaves similar to a human body? ‘Ballistic gelatin’ is used to simulate gunshot wounds in human tissue. It closely simulates the density and viscosity of human tissue. Using a material like that to weigh down the wheel might simulate the suspension losses.
Suspension losses vary with speed (higher/lower vibration frequency), so TOUR‘s rocking rig probably would not work – it simply moves too slowly to replicate suspension losses at normal cycling speeds.
That brings us back to the steel drums. You’d have to make the drum huge to reduce the problems with the convex surface. The drum surface itself would have to be a true replica of actual pavement, not just a diamond tread. You’d probably want to map a bunch of road surfaces with a laser and then use EDM (electrical discharge machining) to engrave an ‘average’ road surface into the steel drum surface. You could make interchangeable plates covering the drum with several road surfaces that feature different roughnesses. And why not a gravel road, too?
Validation

To validate your test rig, you’d take a fast, a middling and a slow tire, and test them on the road, just like Bicycle Quarterly has done. If your drum test results match those on the real road, then you can be confident that they replicate real-world conditions.
Back to Real-Road Testing
tire_test
As you can see, making a useful test rig is a huge undertaking, which is probably why nobody has done it yet. For now, tire companies continue to develop their tires with the help of simple steel drum tests. That may be the reason why they don’t offer their supple high-performance models in truly wide versions: The steel drum tests indicate that you lose performance quickly as you run tires at lower pressures. And since supple, wide tires cannot support high pressures, steel drum tests suggest that wider tires should strong and not supple.
At Bicycle Quarterly, we’ll continue to test tires on real roads. To get good results, we can’t just put a power meter on a bike and go for a ride, then change the tires and repeat. We must keep the conditions the same for all tests. First, this means testing in a controlled setting, like a track. Second, we must control the variables tightly: test only on days with no wind and constant temperature, test each tire multiple times, and do a rigorous statistical analysis of the results.
The statistics are important, because there always will be some ‘noise’ – even in a lab test, because the tire warms up the longer you run it on the machines. The statistical analysis shows where you are recording real differences between tires and where you just see ‘noise.’
After more than a decade of testing tires under real-world conditions, we can say with certainty:

  • Supple casings, more than anything else, determine the performance of your tires.
  • Wider tires roll as fast as narrow ones on smooth surfaces, and faster on rough ones.
  • Higher tire pressures don’t make the bike faster.

There is little doubt about these findings any longer – they’ve become widely accepted, even though the lab tests still haven’t caught up to the new science. But for us as riders, what matters is how well our tires perform on real roads, not on a steel drum.
Further reading:

Continue Reading

Myth 7: Tubeless Tires Roll Faster


When tubeless tires first became available, they were designed for mountain bikes and it was their resistance to pinch flats (above) that made them popular. Off-road, there are few nails or broken bottles that can cause punctures (and even those usually will be pushed into the soft ground rather than puncture the tire), but rims can bottom out on sharp rocks and other obstacles. So much so, in fact, that top mountain bike racers used to race on tubular tires – because tubular rims make pinch flats less likely. Eliminating tubes did the same, and while you still could ‘burp’ the tire, in general, tubeless allowed running lower pressures with fewer problems. Continue Reading →

Continue Reading

How are Compass Tires Different from Panaracers?


From time to time, a customer will ask us: “How are Rene Herse and Compass tires different from Panaracers?” It’s no secret that Panaracer makes our tires – we benefit from the research and technology of one of the best tire makers in the world. Panaracer’s engineers know more about casings and tread rubber than almost anybody, and they translate our ideas into tires that outperform all others in their intended environments.
That also means that it may not be immediately obvious how our tires are different from Panaracer’s own tires, like the Gravelking – or even Panaracer’s budget model, the Pasela. At first sight, with tan sidewalls and black tread rubber, they can look very similar. They are even made in the same factory!

Recently, we had the opportunity to spend some time with Mark Okada from Panaracer Japan (right) and Jeff Zell from Panaracer USA (left). When I mentioned the Pasela, Mark just laughed: “They are completely different tires that have almost nothing in common.” 
I guess it’s the same as asking whether a Bugatti Veyron supercar has the same engine as a base-model Volkswagen Golf, since both engines are made in the same German factory…
What about the Gravelkings, which are available with a tread pattern similar to that of Compass road tires – evidence that the technology transfer between Compass and Panaracer goes in both directions. Jeff said that Panaracer gets the same question, and this is their reply:
“The Gravelkings and the Compass tires are two different types of tires. The reason that Compass tires are so successful is that Jan and Compass have a clear vision for what they want in a tire, and Panaracer has the technology to deliver that. The materials and the construction of the Compass tires vary from the Panaracer line, because of the performance that Compass wants to deliver to the customer. The components that go into the Compass tires, and the processes to make them, cost more, hence the price difference. Both are high-quality tires, but the ride and performance are different. If you’re looking for the most supple tire that incorporates all cutting-edge tire technology, you’ll choose Compass. If you’re willing to sacrifice the ultimate ride quality Compass is known for, to get a little more puncture and sidewall protection, then Panaracer has you covered there.”

Which tire is best for you really depends on your riding style and terrain. Natsuko rides her 30 mm-wide Compass Elk Pass Extralights on really rough gravel with little trouble (above), but if you are somebody who tends to get a lot of flats or destroys tires with rock cuts, we’d recommend the Gravelkings. As the name implies, they are designed for riding on rough gravel, which also means that they can be a bit overbuilt for riding on the road.
The Compass tires (above) are designed for riding on the road, but they also work well – and offer superior performance – on gravel, provided the rider lets the bike move around and doesn’t force it into rocks that could cut the sidewalls. It helps if you ride wide tires. Not only are they faster on rough surfaces, but their lower pressures also make the sidewalls less susceptible to cuts: the tire just deforms when hitting a rock.
Around here, we ride Compass tires – even on our Urban Bikes – because they offer world-class performance while being strong and durable enough for everyday use.
Click here for more information about Compass tires.

Continue Reading

Myth 6: Tread Patterns Don’t Matter on the Road


To celebrate 15 years of Bicycle Quarterly, we are examining 12 myths in cycling – things that we (and most others) used to believe, but which we have found to be not true. Today, let’s look at tire tread.

“Bicycles don’t hydroplane,” declared some experts many years ago. “Hence, tire tread patterns don’t matter on the road.” The first part is true – even wide bicycle tires are too narrow to lose traction due to hydroplaning – but the conclusion assumes that tread pattern only serves to evacuate water from the tire/road interface. Continue Reading →

Continue Reading

One of the 5 Fastest Tires in the World


Recently, the German magazine TOUR published a table showing the ‘five fastest tires in the world.’ We are excited to see our Rene Herse Bon Jon Pass 700C x 35 mm tires (back then still under the Compass label) on this list, in the company of the fastest racing tires. A 35 mm-wide tire on a list that otherwise includes only tires between 23 and 26 mm wide! That by itself is already cause for celebration. It means that our casings really are among the very fastest in the world.
And since all our tires use the same casings and construction, TOUR’s results apply not just to the Bon Jon Pass, but to all Rene Herse tires. I was surprised that they tested the Standard casing. I would love for them to test the Extralight, which we know from our own experience to be even faster.

What is interesting is that the Rene Herse tire scored superbly on smooth asphalt (light gray bars), but a little less well on rough asphalt (dark bars). This doesn’t match our experience, where wider tires provide advantages especially on rough roads. The reason is simple: TOUR tested without a rider on the bike. This measures the hysteretic losses in the tire, but it neglects the (much more important) suspension losses that occur as the rider’s body and bike vibrate. (Click here to learn more about suspension losses.)
This means that TOUR’s testing overlooks one of the main advantages of wide tires: their superior comfort, which also makes them faster. In other words, with a rider on the bike, especially on rough asphalt, the Rene Herse tire probably is even faster than it appears in TOUR’s testing.
We are proud that the Rene Herse Bon Jon Pass scored so well, especially since it is intended as an all-round tire, not an all-out racing tire. The Bon Jon Pass is suitable for gravel racing and has 3 mm-thick tread for many miles on the road. Compare that to the Vittoria with its 0.8 mm-thick tread, which is intended only for time trials, and even then, it’ll wear out quickly.

The excellent performance of the Rene Herse tire shows once again why wide tires have revolutionized cycling: You wouldn’t want to ride the other tires on TOUR’s list on anything but the smoothest, cleanest roads for fear of flats and premature wear. And yet with wider tires, we can ride some of the world’s fastest tires on the backroads where cycling is at its most beautiful.
Further reading:

Continue Reading

Myths in Cycling (1): Wider Tires Are Slower


When we started to publish Bicycle Quarterly 15 years ago, it seemed that most of the technical aspects of bicycles were well-established. And yet, as we tested many different bikes, we started to question many of the things we had accepted as ‘facts.’ To celebrate our 15th anniversary, we’ll look at some of these myths. We’ll explain why we (and everybody else) used to believe them, and how things really work. Let’s start this series with the biggest one:

Myth 1: Wider Tires Are Slower Continue Reading →

Continue Reading

Tubeless-Compatible 650B x 42 mm


The updated Compass Babyshoe Pass TC 650B x 42 mm tires are now in stock in all models. What’s new? We took our most popular 650B tire, and made it tubeless compatible. When you are riding fast on rough gravel, tubeless really makes sense – as I found out when I had dual pinch flats on a Bicycle Quarterly test bike on the original Babyshoe Pass tires (below).

You may wonder how I pinch-flatted on what looks like a smooth gravel road. It was smooth, and so we let the bikes fly on a fast downhill section. Right after a bend in the road, the gravel turned very rough. It was only a short section, but it was enough to pinch-flat both tubes. By the time I had stopped the wobbling bike from a speed of 65 km/h (40 mph), the road was smooth again, as if it all had been a bad dream. At least it was a scenic spot to change the tubes…

While we were making a new tire mold, we also increased the width of the new Babyshoe Pass by 1.5 mm. Now the tires measure a true 42 mm wide on most rims. That makes them the perfect tires not just for randonneur bikes, but also for a whole generation of gravel bikes like the Litespeed T5G and the Cannondale’s Slate.

What about the name? Babyshoe Pass is a 1330 m (4350 ft) high passage between the great volcanoes of Mount St. Helens and Mount Adams in the Cascade Range (above during the recent Volcano High Pass Challenge). The origins of the name are shrouded in mystery, but that doesn’t keep passers-by from hanging baby shoes from the sign (top photo). It’s a great way to travel from Seattle to Portland while avoiding the crowded Puget Lowland.

During challenging rides like this, you will enjoy the Babyshoe Pass TC tires, which roll as fast as racing tires on the paved lower sections of the climb, yet float across the gravel as you cross the actual pass. No matter from which side you ride it, the descent is so steep that speed builds quickly. As you fly across the gravel, you’ll appreciate the possibility to run your tires tubeless. When you don’t have to worry about pinch flats, you can even look up from the road and see glimpses of Mount Adams snow-covered cone. Of course, like all our tubeless-compatible “TC” tires, you can also run the new Babyshoe Pass TC with tubes.
The original Babyshoe Pass (without the “TC” in the name) remains available as long as supplies last. It’s a little lighter, a little narrower and a little cheaper than the new model.
Click here for more information about Compass tires and the new Babyshoe Pass TC.
 

Continue Reading

Ultra-wide tires: Unfair advantage in ‘cross?


Last weekend was the first cyclocross race in Seattle. Almost every year, the first race catches me by surprise. Summer is over? It’s ‘cross season already?
Usually, I oil the chain on my trusty Alan ‘cross bike and head to the races. This year, the Alan’s tubular tires needed regluing. The glue must cure for 24 hours, and the race was too close for that.

What to do? I looked at my Firefly, still dusty from the Volcano High Pass Challenge and the Bicycle Quarterly Un-Meeting. What if I raced it instead?
The morning of the race, I took off the low-rider rack and two bottle cages, then rode the 25 miles (40 km) to the start. I arrived with just enough time to remove the last bottle cage, unclip the underseat bag, and do a practice lap. I let some air out of the tires, and then it was time to race.
At the start, I was a bit nervous, because I had forgotten to swap my touring pedals for dual-sided mtb pedals. On the bumpy course, clipping in after a remount wasn’t easy. I knew I’d lose some time. And I worried about the grip of my “road” tires at race speeds on the loose stuff, especially the grass. I had entered the Category 4 race. It’s the lowest of the three categories offered, but the fastest racers come out of a season of road racing and are quite fast.

Then we were off! I’ve never been an explosive sprinter, and so I found myself somewhere around 15th position as we went into the first corner. A long straight followed, and I was surprised by how fast my bike went. I know what bumpy grass feels like on 34 mm tires, and it was a totally different experience on 54s. Instead of bouncing, I was able to put down power and ride smoothly.
I had moved up to 3rd position when we reached the first sandpit. And since I hadn’t been working as hard as the others on their narrower tires, I could outrun them. (In the deep sand, even my 54 mm tires didn’t provide enough floatation to make riding more efficient than running.) I took the lead at the exit of the sand pit and never looked back (top photo).

I ran through the next sand pit, too, but the third one was relatively short, and I found that momentum carried me across. Just accelerate hard on the approach and keep going! Where the course doubled back on itself, I could see my pursuers. I was surprised how quickly my gap had grown. I would like to claim superior fitness, but I think the bike’s speed deserves more credit. I’ve raced Cat. 4 in the past, and I’ve never experienced such a speed difference.

With so much grip, I rarely touched my brakes. I did realize why ‘cross bikes have higher bottom brackets: After leaning deep into a corner, I righted the bike until I thought that I was straight again. When I started pedaling, I was still leaning much further than I thought. I clipped a pedal, and next thing I knew, I was on the ground. My lap times show that I lost 10 or 15 seconds, and my pursuers came back into sight. But adrenalin enhances performance, and I managed to hold onto my lead to take the win after 42 minutes of all-out racing.
What did I learn? First, on bumpy terrain, wider tires are much faster. We already knew this, but the magnitude of the effect surprised even me. Being able to pass other racers at will really represents an unfair advantage. Cornering grip on the loose, but dry, surfaces also was far superior to what I am used to.

What about the lack of knobs on my tires? We know that on gravel, knobs don’t make any difference, and I found that the same holds true on dirt and even dry grass. Perhaps I shouldn’t have been surprised: Traditional dry-weather ‘cross tires (above) have almost no tread – in fact, they are so smooth that we used to ride them on the road, since they were a little bit wider than the 21 mm racing tubulars we had back then.
Of course, riding the Firefly with its 54 mm tires in a ‘cross race is unfair. The best rider should win, not the rider on the widest tires. Road racing and its muddy cousin, cyclocross, are traditional sports, and the bikes are clearly defined by the rules. It may be possible to make faster bikes, but finding the fastest bike isn’t the point of racing – it’s finding the fastest rider. As BQ contributor Hahn Rossman (below) put it: “Cross is about riding a road bike off-road. You really shouldn’t ride across bumpy terrain on narrow tires, but it’s great fun.”
Cyclocross has an element of underbiking, and that is why the UCI has limited tire widths for professional racers. For amateurs in the U.S., the UCI rules usually don’t apply, but I feel it isn’t in the spirit of the sport to ride a bike that is so blatantly outside the accepted norm.

I am also not sure my advantage would persist as the weather turns rainy. On a muddy course, my ultra-wide tires may not work so well. A narrower tire – say 35 to 40 mm wide – digs into the mud and probably creates more lateral resistance when cornering. A super-wide tire may just skate across the muddy surface without finding any grip. Once the weather turns muddy, I could put a set of mountain bike knobbies on the Firefly to find out.

Or I’ll just ride my Alan (above) again, because it’s already set up for muddy riding. In the end, my experiment hasn’t shown anything we didn’t know already: On bumpy surfaces in the dry, wider tires are much faster. We also know that in mud, you need knobs to dig into the surface and generate grip.

If you have been intrigued by cyclocross, give it a try. It’s great fun, and what you learn about bike handling will improve your skills on all surfaces, year-round. Don’t worry if you don’t have a cyclocross bike. Just ride the most suitable bike you have. Cyclocrossers are very relaxed about the competition – nobody complained that I rode ultra-wide tires. Last weekend, old road bikes, a randonneur bike (with the fenders removed), and mountain bikes mixed it up with the purpose-built ‘cross bikes.
And if you need cyclocross tires – whether for dry or muddy conditions – our Steilacoom 700C x 38 mm and Pumpkin Ridge 650B x 42 mm knobbies are hard to beat. I just wish they fit my old Alan, which dates from a time when 28 mm tires were “huge”. It would save me from having to re-glue my tires!
Photo credits: Westside Bicycle (Photos 1, 3, 4, 5), Natsuko Hirose (Photo 8).

Continue Reading

New Tire: Pumpkin Ridge 650B x 42 mm


Many cyclists dream of a dual-purpose tire that rolls smoothly on paved roads, but has knobs that dig into the surface when it gets slippery. In the past, combining these two qualities in a single tire has been elusive. Usually, the knobs were too squirmy for good performance on pavement – especially when cornering hard – and yet the knobs were spaced too closely to shed mud when the going got rough.
When we designed our first knobby tire, the 700C x 38 mm Steilacoom, we made the knobs big enough so that they don’t squirm, but left enough space in between to clear mud. We distributed the knobs so that the tire always is supported by the same amount of rubber, whether it’s rolling forward or leaning into a turn. This gives you uniform grip at all times.

Does it work? Even we were surprised how well the Steilacoom rolls and how hard you can lean it into corners (above). If it weren’t for the (unavoidable) noise of the knobs, you’d soon forget that you were on knobby tires at all. I am aware that this sounds too good to be true, so I gave the Steilacooms to other riders to test. Mark’s initial comment was: “Why would I ride knobbies on a paved ride?” When he rode the tires, he was surprised how “un-knobby-like” they felt on pavement. And gravel racer Matt Surch found that he had no trouble keeping up with fast road pacelines on Compass knobbies. Both these riders confirmed that the Compass knob pattern works exceedingly well on pavement.

What about mud? After all, the whole point of a knobby isn’t just to ride on pavement, but to provide extra traction when conditions get slippery. A full season of cyclocross, including the single-speed world championships, have shown that the knobs have no trouble shedding mud. Your bike will get dirty, but your tire tread stays clean – as it should be. And the knobs are tall enough to dig into the surface and provide excellent traction.

With so many Allroad bikes running 650B wheels these days, it made sense to offer the same tread pattern in a 650B tire with a little more volume. Enter the Pumpkin Ridge 650B x 42 mm. We named it after Pumpkin Ridge, a quiet paved road near Portland, Oregon, that has a number of promising dirt spurs heading toward the Tualatin Mountains. Past explorations failed to reveal a connection, but filled our fenders with mud. We wished for knobby 650B tires that would not get bogged down in the mud, yet would also roll well on pavement. Imagine where you might go with these tires….

The Compass Pumpkin Ridge is designed for rides that mix pavement, gravel and muddy dirt. “Road” tires quickly reach their limits here, yet if you ride knobbies, the paved sections of the ride aren’t much fun. The Pumpkin Ridge performs equally well on all these surfaces. And of course, if you race cyclocross on 650B wheels, like BQ Team rider Steve Frey, there finally is a tire that offers the ultimate in performance in that wheel size.
The Pumpkin Ridge is now in stock, in Standard and Extralight casings. Click here for more information or to order.

Continue Reading

Tubeless-Compatible 650B x 42 mm


If there is such a thing, Babyshoe Pass is our favorite tire here at Compass and Bicycle Quarterly. It’s 42 mm width gives it great cornering grip, comfort and puncture resistance. The 650B wheel size offers nimble handling with wide tires. The Babyshoe Pass is named after an iconic gravel pass in the central Cascade Mountains, because it’s great on gravel, too. Virtually everybody at Compass and on the “BQ Team” rides more than 90% of the time on these tires.

The Babyshoe Pass is an obvious choice for modern Allroad bikes. Some, like the Cannondale Slate, already are equipped with 650B tires, and they can realize their true potential with a set of supple tires. Others are designed around 700C x 35 or 38 mm tires, but 650B x 42 fits nicely and provides more air volume for gravel, as well as more nimble handling for paved descents. It’s a win-win situation, as evidenced by the Bicycle Quarterly test bikes that were equpped with these tires (above).

Being intended for pavement and gravel alike, the Babyshoe Pass tire always was an obvious choice for tubeless. However, tubeless-compatible tires have a different bead, so this required a new mold. We first wanted to gain experience with our other tubeless-ready tires before we replaced the molds for the Babyshoe Pass. Now that time has come…
When we designed the new mold, we increased the size of the Babyshoe Pass by 1.5 mm to make it a true 42 mm wide on most rims. If you mount it tubeless, it will be a little wider yet.
Currently, the new Babyshoe Pass is in stock with the “standard” casing. Later this year, the Extralight version also will get the tubeless-ready bead and extra width.
Click here for more information or to order.
 
 

Continue Reading

Two Years of Racing on Compass: Interview with Matt Surch


Long-time Bicycle Quarterly reader Matt Surch (above) put his name on the map when he won last year’s Steaming Nostril gravel race on Compass Bon Jon Pass tires. We checked back in with him to see how the tires performed in the year since then, and to hear about his road racing on Compass Cayuse Pass tires.
JH: With another season of riding and racing on the Bon Jon Pass tires, how do you feel about them?
Matt Surch: Frankly, the Bon Jons have been exactly what I’ve been hoping for in a gravel tire. This comes down to two key aspects: 1) volume – 35 mm is perfect for so much of the riding I do off paved roads. 2) tubeless – I love this format for its road feel and flat resistance. One of the things I’m really enjoying with the Bon Jons is that they are perfect for the rides where I head out the door without much more of a plan than to ride fun stuff. That tends to mean taking paved roads up to Gatineau Park, then piecing together spans of trail, some of which are very old dirt roads, in novel ways. I just go where I feel like going, try branches I don’t know, discover things. While the 32s are a bit small for rides like this, and the 38s bigger than required, the Bon Jons are the Goldilocks option: just right.
The Bon Jon has become my go-to for gravel, and I have them mounted on wheels that are on my cyclocross/gravel bike all summer. I have a pair of 32mm extralight Stampede Passes on another steel all-road bike for paved rides that I don’t need my aero road bike for.

Tell us about some memorable rides or races on these tires.
Sure, I have a couple that come to mind, from perhaps opposite ends of the spectrum. The first was our big annual local criterium in Ottawa’s Little Italy neighborhood, the Preston Street Criterium. This was the 44th edition of the race, which draws the best crit racers from Toronto and Montreal, in addition to our locals. I can still remember the first time I visited the crit, about 15 years ago, with my friend and longtime Compass tire evangelist, Rodd Heino. I barely touched my road bike then, and didn’t even consider racing.
I only took up racing criteriums in 2015, in fact, after waiting until I was sure I could ride at the front of the local training races as much as I needed in order to stay safe and learn the ropes. So last year, on Father’s Day, I raced the Preston St. Crit for the second time in the ‘Pro’ race. As I’d been doing all season, I was on the 26mm Compass Cayuse Pass Extralight tires on my Cervelo S5 aero road bike, mounted onto 55 mm-deep carbon Woven Precision Handbuilts wheels. This is a pretty aerodynamic set-up, and I’ve been very happy with this combination.
The race was pretty incredible. I missed the breakaway of 4 guys that went out about 30 minutes into the race, and decided to bridge up to them. One rider came with me, and we worked really hard together over the longest 8 minutes of my life to connect. The whole time friends and family were cheering me on so hard from the sidelines. I actually feel emotional as I write this….
We rode the rest of the race as a group of 6, ultimately lapping the field. Into the final turn I felt good and was positioned third, behind the two best sprinters. In an instant, I was sliding across the pavement. I’d slid out, not focusing enough on my cornering technique as we hit the final turn faster than any other lap. I lost a lot of skin and literally burned through my much-loved Giro SLX shoe, but my bones and bike were fine. My family found me, and they and a few guys from The Cyclery, one of Ottawa’s best bike shops, took care of me. I jumped back on my bike to salvage 5th, which was a bit of a consolation (I made a bit of money to help pay for repairs to my kit), but was just really happy to have delivered a peak performance that was only marred by one mistake. And having my family and everyone there supporting me was really special.

The other day that stands out was rather different. Iain Radford (fellow Compass devotee) and I decided to organize a gentleman’s race over an awesome road/off-road route at the beginning of July. Some of the most fun we’ve ever had on bikes has been when riding this format – teams of 4-6 riders team time trialling a big, hard route, unmarked, unofficiated – so we wanted to put one on. Our Ride of the Damned event is run in a team format, too, but it’s not a race. This time, we wanted to race.
We sketched out a route for a recon ride at the end of June and hit it up as a group of 4 on a rainy Sunday. I was on the 38 mm Compass Barlow Passes, Extralight (above), with Challenge latex tubes. I ended up with a tiny puncure on a rock, which I put down to the tubes being stretched so thin. The feel of the route wasn’t quite right, there was too much pointy rock on some of the sections of trail we used, which really interfered with the flow of the ride. We opted to tweak it, removing the pointy rock bits, and landed on a 117 km route that alternated between pavement, trail, and dirt road sectors.
On the morning of the event, El Camino, we had ten 4-man teams pre-registered, and we all headed off at roughly one minute intervals. My team was well balanced, and we leveraged our strengths well, riding mellow on the climbs, and absolutely drilling it everywhere else. It was a really hard effort on the bike, but so much fun! I’d opted to run the Bon Jons in tubeless format instead of the larger 38s with tubes, and this worked perfectly. Iain punctured, which saw us passed by a number of teams, then we chased them back down. It was exciting! At the end of the day we secured the fastest time, 3:51, beating our goal of 4 hours.
But the fun didn’t end there. We had everyone bring BBQ stuff, and got the grill at the park going for a great party after the ride. It was really simple logistically, and tons of fun hanging out after the ride as teams streamed in. Of all the racing I’ve done, this format is the most fun, I love it. Rather than a team working for one rider, everyone contributes to the whole team’s result. It requires a lot of strategy, it’s a bit of an art, like team trialing on the road, but more technical!

You run the tires tubeless. Any tips on how to set them up? What rims do you use?
Yes, I run the Bon Jons tubeless. I’ve had them on 55 mm-deep carbon Woven Precision Handbuilt wheels (above), which use a different tubeless bead design, so there has been a bit of a learning curve. The wheels are designed with a fairly deep centre channel for easy of tire mounting, with a tubeless bead shelf that has a lip on the inside, along the channel, for the tire bead to climb over when inflated. Early on, I realized that I needed a bit more tubeless tape than required for sealing the rim. I was having some trouble airing the tires up, which can be caused by a weak compressor or obstruction in the valves. I added another layer of tape (Gorilla tape, in fact) to see if that’d do the trick. It did, the tires mounted immediately when I beefed up the channel this way. So this is my #1 tip: if you don’t have a snug fit at the channel, add tape and try again.
The other tips are standard:

  • Use a bit of water on the bead when mounting, it really helps. I don’t bother with soapy water, but just grab a bottle and drop some onto the tire.
  • Remove the valve core of your tubeless valve when mounting the tire. I use the air-gun nozzle on my air compressor, sticking it into the valve. This allows more air to pass through.
  • Don’t put sealant into the tire until you’ve mounted it. Trust me on this, you don’t want that stuff spraying all over you, it stains! Air up the tire, get the beads locked in, then use an injector to put sealant into the tire. I use one scoop of Stan’s regular formula sealant.
  • You really need to shake the tires all over the place, especially on their sides, to get complete sealing. I’ll do that, then rest the wheel on its side for an hour or more, then flip it. This works well. Sometimes you actually need to ride a tire a bit to get it to seal. This isn’t a Compass-specific thing.
  • If you don’t have an air compressor or access to one, yes, you can use CO2 to air up your tubeless tires. Obviously, this is wasteful and more costly than using a compressor. But it will work for a tire with a tight enough bead. DO NOT inflate with CO2 with sealant in your tire; the sealant will solidify into a ball. If you use CO2, let it all out after locking the beads, then replace with air.
  • If you use a carbon rim, don’t overtighten your valves. If you do, you can deform the brake track, which you’ll feel under braking. Silca makes a nice valve set with a fairing that helps reduce the possibility of creating this deformation.
  • If you don’t ride wheels you’ve set up tubeless often, your sealant will dry up sooner than if you ride it regularly. If you only use one scoop of sealant, odds are it’ll be mostly dry when you’re riding. You’ll want to make sure you keep some liquid sloshing round in the tires. Always bring at least one spare tube, two for more risky rides.
  • Tubeless sealant really only seals small holes, like those from glass, thorns, wire. Medium-sized (a few mm long) can sometimes be sealed with the help of some cotton or similar fabric. Cut some small strips from scrap fabric at home (I’ve recently tried a cloth number plate/dossard) and pack them into your flat kit. If you puncture, try poking that fabric into your tire to create a dam for your sealant to seal around/soak into. This is best done while the tire is still fairly well inflared. I’d have this work, as have others, it’s worth a shot.
  • You’ll need to air the tires up pretty high to get the beads to seat – this is normal. Bring the pressure back down to where you like it after seating the bead.
  • Experiment with your air pressure. For very light tires like the extralight Compass Bon Jon, the sidewall is so compliant you’ll need a bit more pressure – with tubes or not – than you might imagine. Start on the firm side, then gradually drop your pressure during a ride until you find the best balance of ride feel you are looking for.
  • Experiment, this is how you’ll get the most from your tires, and remember, tires cut more easily when their pressure is high.


Are you still on your first set of tires? Or if you replaced them, how many kilometers/miles did you get out of them?
I’m on my second set of Bon Jons now, but after 3000km my first pair are still rolling on my old bike. I mounted a fresh pair of the tan-walls on my new Brodie Romax (above) in the spring, and they’ve been perfect ever since.
Any durability concerns?
No, I have had no durabillity concerns whatsoever, I’ve been really pleasantly surprised. I find climbing is the toughest on tires for wear, and most of the climbing I do on this bike is on unpaved roads, which is why I think I’m getting quite good wear out of them. Because the tread wraps around the tire well, I don’t have any sidewall damage, which is somewhat incredible considering some of the trails I’ve ridden!
What tire pressure do you run? And how much do you weigh?
I weight about 172 lbs in the spring… up to about 177 lbs during the season. I used to run 50 psi rear, 47 front on the Bon Jons, but now I tend to run closer to 40. I spent a week in South Carolina riding big climbs and fast descents, and settled on about 55 psi in the 32 mm tires, which felt fantastic in the turns…

Our tires have a tread pattern that is optimized for road use. How do you find their grip on dry gravel?
Yeah, good question, I think this is something a lot of people are wondering about. I learned years ago at the Deerfield Dirt Road Randonnée that tread doesn’t do much for you on gravel. I rode 28 mm Grand Bois tires the first year there, then the 32s. Same tread, more volume with the 32s. On the descents, I didn’t have grip issues with either, but the loose climbs were always where the challenge lay. It was clear that more volume, more tread on the surface, was key. So I kept going up in size as I was able to get bigger tires on bikes, and confirmed that volume is all that matters for gravel. When the substrate is not locked in place, knobs have no effect. It’s like snowshoeing: all about surface area.
The tricky part comes when we need to deal with routes that have a mix of surfaces: pavement, gravel/dirt road, and trails. Trails, when gravelly, are fine with no tread. But knobs become useful if they have something to cut into. Slick patches of mud are an example. The standard Compass tread is scary on these, one has to ride completely upright. A bit of tread can cut through a bit of mud and dig into dry dirt below. On snow and grass, a little tread goes a long way too. At the Steaming Nostril race last year, we had some grass on the course, and I really had to use a lot of energy to keep moving with just the “Road” tread. But it was worth it! On the snow side – I know some are thinking, ‘What the….’ – the 2015 Rasputitsa Gravel Road race had an extended packed snow/ice sector that we absolutely HAD to use a file tread tire for. That was a shame, as the rest of the course would have been faster on the Compass tread.
On the El Camino route we capped things off with a very steep gravel trail climb, which kicks up to 23% in grade. With the Bon Jons I made it up, despite having no knobs on the tire. It was more a matter of smooth power transmission than tire grip.
When we face exposed rock, especially wet, we also tend to want some tread. A file tread tends to work well for this, as they have so many little edges.
I’ve recently spend some time on the 650B Switchback Hill 48s and 42 mm Babyshoe Passes, since my new cyclocross / gravel bike has disc brakes; I can run different wheel diameters. Both these tires climb really well on loose surfaces, due to their volume. That volume can also make them a little skittish on corners with pebbles over hardpack, which allow narrowed tires to cut to the firm surface more readily. That’s not a matter of tread, but width. I’m very much looking forward to trying the new Pumpkin Ridge 42mm 650Bs on mixed terrain, which will definitely work well in mud.

During the road racing season, you’ve been riding our Cayuse Pass 700C x 26 mm tires. How have those tires worked for you?
I’ve been riding the 26 mm Cayuse Pass tires on my Cervelo S5 aero road bike for almost two seasons now, and they have been somewhat transformative. Previously, I used Hutchinson’s tubeless tires on the bike, which were wooden, but reliable. In 2015, I used Continental GP4000s and Michelin Pro Race 4s. I punctured all but one of these tires badly enough to write them off. They were all 23 mm tires on my 19 mm (internal width) Woven wheels. While the Contis test very fast for aerodynamics and rolling resistance on rims like mine, in practice, I found them ill-suited.
The problem is that their tread – and this is true for the Michelins too – does no wrap around the casing enough to protect the tire’s casing. The tires handled well, somehow, but I had all kinds of flats on the shoulder of the tires. Because they were 23 mm tires (their 25s were too big for my frame/fork), they were somewhat squared off on my rims, and I had to run 100psi to avoid pinch flats. But this created too much casing tension, which makes it easier to cut the tire! In the spring, I was delighted to discover that the 26 mm Cayuse Pass fit my bike, so I’ve been on them all season. I experimented with pressure, working down from 95 psi to 80, where I’ve stayed. Wow, what a difference! I’ve got more grip, lower rolling resistance, and my bike feels so much more comfortable than it used to. I thought it would always suck on long rides, especially on typical roads with cracks, but I’ve found myself grabbing the bike so much more often, because it feels good. I’ve had only one flat on these tires in about 5,600 kms, a pinch on a pothole in the dark. I’ve still had no flats on the Bon Jons.
So, on top of being far more reliable than what I used to use on my road bike, I’ve found the Cayuse Passes roll really fast, and any aerodynamic hit I’ve taken as a result of them being a little wide for my rims and taking up more space within my frame and fork are outweighed by their fast rolling, grip, and reliability. I’m stoked to be on these tires, and don’t plan to change. I used to wish for a tubeless version of these tires, but now I am happy to stick with latex tubes. It’s hard to argue with no punctures in two years.
I wish I had a power meter, because I’d love to compare the Bon Jons on my CX bike against the Cayuse Pass. They feel slower on smooth paved roads, but I want quantification of the difference, ideall on the same bike. When it comes to our highest speed and intensity races, the crits and road races, I still feel I need to favour my system’s aerodynamics, and the 26s are the max I can fit in my Cervelo. But what if that bike was designed to be optimal with 28 mm, 30 mm, or 32 mm tires? Would it be as fast? I wish I could find out…
You’ve been trying the knobby Compass Steilcoom tires lately. How did that go?
I wanted to use the Steilacooms at the Steaming Nostril this year – our region was getting epic rain, and we experienced swampy conditions. But first I had to build my confidence in their pavement performance. I’d seen your post about them, so I was cautiously tentative. Results were good! I found that the faster I went, the better they rolled, as they sort of plane above 25-30 km/h, and really hum along around 40-45. We had some fast corners to deal with, one totally sand-covered, and I had zero issues. The profile really is great for cornering on the road. Ultimately, I was able to ride where I wanted to be and pull as long as I wanted to pull the whole time, and it was a total succes. I won’t make a habit of riding them for smooth stuff like this, but I am stoked that they are able to perform well on pavement, gravel and in mud.
You placed 2nd in this year’s Steaming Nostril. How did the Steilacoom tires perform in the actual race?
The Steilacooms performed really well in April at the Steamin Nostril. I had to make a tough call, between them and Bon Jons for race day. The region had seen a lot of rain leading into the race, and I was expecting the crux section to be waterlogged and slippery. Knowing that was where I’d want to break away from the front group and try to go on solo for the remaining 10k or sp to the finish, I opted for the Steilacooms. Ultimately, the section was quite dry, and I didn’t wind up needing the knobs. I managed to break away and went for it solo, but was fading into the wind as Sjaan Gerth pursued me, ultimately overtaking and holding me off for the victory. The Bon Jons would have been the faster tire on the day, but it was a game-time decision, and sometimes you just have to roll the dice and see. The Steilacooms were incredibly good in a few cyclocross races I did in 2016, and I remain really fond of them. I might just have to shave some down over the winter…
If we made a tire that isn’t in the program yet, what would you like to see from Compass in the future?
My dream tire, if I could pick just one, would be based on the Bon Jon casing (tubeless, same size), and add a file (diamond) tread. That would allow me to use the Compass tire for most of the gravel rides and races. The Continental CX Speed tread is probably the closest to ideal I can think of. There would still be some events that required more volume and tread, but a file tread would cover the bigger existing gap. It would also be a more sure-footed feeling tire for those less comfortable with a bit of sliding out there on unpaved surfaces!
We’ll consider that. Thank you very much, Matt, and good luck with the other races this season!
Further reading:

Photo credits:
All photos by Matt Surch, except:
1. Preston Street Criterium 2016
6. Rasputitsa Gravel Road Race 2016
7. Grégoire Crevier, Canadian Criterium Championships 2016

Continue Reading

Choosing Your Tires


We’ve experienced a profound revolution in road bikes in recent years: It used to be that to go fast, you rode narrow tires and pumped them up to the maximum pressure. If you wanted more comfort, you used wider tires and (maybe) lower pressures, but you knew that you’d be slower.
Now we know that comfort and speed aren’t opposed, but inextricably linked: A bike that absorbs shocks better rolls faster. Narrow tires don’t have any speed advantage, and inflating your tires to the maximum often makes your bike slower.
But what does this means in practical terms, when it comes to choosing new tires for your bike? Do you need to get a new bike with clearances for ultra-wide tires? Or is there a way to benefit from the “tire revolution” on your existing bike?
The simple guidelines below are based on more than a decade of research into the performance of tires, and they’ve proven themselves on the road time and again.

Supple Casing
The most important part of the “tire revolution” is the supple casings. In the past, we thought that supple casings and wide tires didn’t go together well, because supple, wide tires have to be run at relatively low pressures. Now we know that lower pressures don’t make tires roll slower. And that makes a supple casing better in the two important areas of tire performance: A supple casing has less resistance as it flexes (hysteretic losses) and it transmits less vibrations from the road (suspension losses). It’s a win-win scenario.
Compared to the casing, all other factors – width, tread thickness, weight, etc. – are of minor importance. In Bicycle Quarterly‘s tire tests, the five fastest tires ranged in width from 24 to 36 mm, but they all had one thing in common: a supple casing. In practical terms, this means that a supple 25 mm-wide racing tire will be more comfortable and faster than a 42 mm touring tire with stiff sidewalls.
So don’t fret if your bike can only fit relatively narrow tires. Just get the best, most supple ones you can find, and enjoy most of the benefits of the “tire revolution”.

Width
When in doubt, use wider tires. At least up to 42 mm, wider simply is better. More grip, more comfort, same speed, fewer flats. What about the aerodynamics of wider tires? In our testing, both in the wind tunnel and on the test track, we found the effect too small to measure. And when you factor in the greater shock absorption (lower suspension losses) of the wider tires, it’s likely that any small increase in wind resistance is made up by the smoother rolling of the wider tires. On smooth roads, it comes out the same, on rough surfaces, wide tires are demonstrably faster.
Of course, you’ll have to work with the clearances of your bike. Don’t try to squeeze the largest possible tire in there with just a hair’s breadth of clearance. Your tire may “grow” with age or your wheel may go slightly out of true. I recommend a minimum of 3 mm clearance all around the tire. When in doubt which tire will fit, go with a slightly narrower one. If you find that you have more clearance than expected, get the bigger size the next time around.

Wheel Size
When you get a new bike, wheel size is an important consideration. Smaller and/or lighter wheels will be more nimble, larger and/or heavier wheels will be more stable. Ideally, your bike is both stable and nimble: It should stay faithfully on a chosen line, but it shouldn’t resist if you want to change its trajectory. How do you achieve that?
The forces of trail and wheel flop cancel each other, especially on a bike without a front load. That is why the wheel size plays such an important role – you can’t really compensate for a front wheel that is too large or too small.
The bike industry is only slowly waking up to this. Too many gravel bikes still come with the same 700C wheels that you find on racing bikes with much narrower tires. Smaller 650B wheels are a better choice for wide tires – from 40 to 50 mm –  and for even wider tires, I prefer 26″ wheels. That way, you can enjoy the nimble feel of a good road bike and the surefootedness of wide tires…
If you use ultralight carbon rims and superlight tires (like our Compass Extralights), you can go up one wheel size. The larger diameter compensates the light weight to keep the rotational inertia in the “optimum” range.

My “dream bikes” are equipped with either 650B x 42 mm tires (left) or 26″ x 54 mm, depending on whether they will see mostly paved or mostly gravel roads. But in practical terms, I am perfectly happy on a bike with 700C x 32 mm tires (right), provided the tires are supple performance models and not sluggish “touring” tires.

The importance of supple casings isn’t a new discovery. For almost a century, professional racers have ridden supple, handmade tires, no matter whether the fashion was for 30, 20 or now 25 mm-wide tires. In fact, tires are the only thing that hasn’t changed significantly on pro racing bikes during the last 70 years. You could put Fausto Coppi’s tires on Christopher Froome’s bike, and he’d never know the difference.
Outside the pro peloton, the importance of supple tires was largely forgotten as riders became more concerned about flat resistance than the joy of gliding along on a cushion of air. Only recently, supple clinchers have become available that offer the feel and performance of great racing tubulars, but in much wider widths.

Speaking of flats, that is the one drawback of staying with narrow tires. Since they run at higher pressures, they are more likely to puncture. And yet, in my experience, the fear of flats is often overstated. On the beautiful backroads that offer the best cycling experience, flats are relatively rare.
Debris accumulates where cars don’t go, hence you get so many flats when riding on the shoulders of busy highways. On backroads, you ride in the traffic lane (but with little traffic, you don’t bother anybody), so there isn’t much debris that could puncture your tires.
downhill
To summarize, you don’t need a new bike to enjoy the “tire revolution”. For your existing bike, choose tires with supple casings, and use the widest model your bike can fit with safe clearances. And when it’s time to get a new bike, consider getting a bike designed for wider tires and perhaps smaller wheels to get the performance of wide tires with the nimble handling that makes a good racing bike so much fun. It’s that simple!
More information:

Photo credit: Goggles & Dust / Brett Horton Collection (classic racers).

Continue Reading

Compass 700C x 35 mm and 38 mm Back in Stock


The long days of summer see us heading far into the mountains. Often, our ambitious plans push the limits of even the longest days… Above, Natsuko descends the incredible chain of passes in the Cevennes mountains of France. This amazing tour is featured in the latest Bicycle Quarterly.
Just in time for the adventures of the summer, our latest shipment of Compass Barlow Pass 700C x 38 and Bon Jon Pass 700C x 35 mm tires has arrived. We appreciate your patience while demand outpaced supply during the last few weeks. All of us at Compass Cycles work hard to keep all our products in stock at all times. Because for us, excellent tires are essential supplies for great rides.
Click on the links below for more information about:

Continue Reading

The Trouble with 'Road Tubeless'


It’s always interesting when bike industry people talk among each other, off-the-record. On the ride from the airport to Paul Camp a few weeks ago, one bike tester was still visibly shaken when he related: “My tubeless tire blew off the rim yesterday. I almost crashed.” Worried that this might have been one of our tires, I asked about the brand. He mentioned a big maker, known as a pioneer of  ‘Road Tubeless.’ The tester continued: “I had it inflated to 90 psi, well under the max. I was just riding along, when suddenly – bam!”
Tubeless tires are becoming popular these days. Using inner tubes inside your tire almost seems like a throwback to the 1950s. Cars have not used inner tubes in over half a century, and mountain bikes have gone tubeless, too. Many of us have been riding our Allroad bikes, with their wide tires, tubeless for years.
Finally, road bikes, with narrower tires, are going tubeless, too. But it hasn’t always been smooth sailing: There are more and more reports of tires blowing off the rims. What is going on? Why are tires with inner tubes safe at high pressures, but the same tires sometimes blow off the rim when mounted tubeless?

An inner tube doesn’t just hold air, it also reinforces the joint between the tire and the rim. Air pressure pushes the tube against the tire so that it no longer can move independently. For the tire to blow off, a very small section of the tube must stretch tremendously, so the tire can climb over the rim’s edge. As flexible as inner tubes are, they get to a point where they don’t stretch any farther – pull on a tube, and you’ll notice this. That makes it very hard for the tire to blow off the rim.
Without an inner tube, there is nothing reinforcing that joint. If the fit between rim and tire is even just the slightest bit loose, the tire can slide upward, and – bam! In fact, even with a perfect fit, there is a point at which a tire blows off the rim: Tire beads can stretch a little, and the higher you inflate the tire, the more force there is stretching the bead. That appears to be the root cause of the problem: Road tires typically are run at relatively high pressures.

Thinking about this, I realized that ‘Road Tubeless’ is a bit in uncharted waters: Usually, tubeless tires run at much lower pressures. Tires for cars and motorcycles are generally inflated to less than 45 psi. (The exception is airplane tires with up to 200 psi, but those are a very special design.)
All these tires also are much stiffer than bicycle tires, which helps them stay on the rim. A supple tire can move in just one small spot, which makes it much easier to climb over the rim’s edge. I was surprised at Paul Camp to hear about the tester’s experience with a tire that isn’t even known for its supple casing. But compared to car or motorcycle tires, even stiff bicycle tires are supple…

To test the limits of our tires with tubeless mounting, I installed a Compass Bon Jon Pass 700C x 35 mm tire on a wheel that we had measured carefully to make sure its diameter was exactly to spec. I inflated the tire to its maximum pressure of 90 psi (6.2 bar) – without problems. The pressure has already gone down to 85 psi by the time I took the photo – there was no sealant in the tire for reasons that will become apparent in the next paragraph.
I then inflated the tire further. 100 psi was fine. 105 psi, no problem. A few more pump strokes, about 108 psi, and – bam! The tire blew off the rim. I was wearing ear protection, and there was no sealant inside the tire, so no damage was done.
Of course, few people would inflate a 35 mm tire to 108 psi (7.6 bar). Even with tubes, the Bon Jon Pass is rated to a maximum of 90 psi (6.2 bar). And as long as everything is perfect, you can run them tubeless at this pressure, too. But in the real world, not everything is perfect. The diameter of different rims can vary considerably. We’ve found that the rims on many production bikes are a bit smaller than spec, because that makes it easier to mount the tires on the assembly line. Of course, this also results in a looser fit of the tires. If you build up the rim bed with extra rim tape – some mechanics even use thicker ‘Gorilla Tape’ – you can improve the fit of the tire on the rim.

Over the last year, I’ve been testing every model of tubeless-compatible tire in the Compass program. I’ve mounted them without tubes on a range of bikes, both Bicycle Quarterly test bikes and my own machines. I’ve experienced zero problems, but I also run them at pressures of 60 psi (4 bar) or lower. I remounted the Bon Jon Pass that blew off the rim and inflated it to 60 psi, put in some sealant, and took it for a couple of rides. As expected, it was fine. (However, we don’t recommend reusing tires that blew off the rim, as the bead can get damaged.)
Based on this experience, we recommend: Do not exceed 60 psi (4 bar) when running Compass tires tubeless. If you need higher pressures, please use tubes. Since the problems with running tubeless tires at high pressures are not limited to Compass tires, I’d recommend this for all tubeless tires – and especially for high-performance tires that are relatively supple.
BJPASS_result-750x481
However, you also don’t want to run too low a pressure with tubeless tires. If the tire flexes excessively, this will break down the casing until it starts to leak (above). With a narrow tire, you have a narrow window between “too high” and “too low” pressures. On a 35 mm tire, 60 psi (4 bar) still is plenty for most riders. (I usually ride my Bon Jons at about 35-40 psi.) But if we were to offer a 26 mm-wide tubeless-compatible tire, 60 psi isn’t enough even for a light rider. Yet going higher than 60 psi would risk blowing the tire off some rims.

With wider tires, you don’t have that problem. I run the 54 mm-wide Rat Trap Pass tires on my Firefly at 40 psi (2.8 bar) on smooth roads. At such a ‘high’ pressure (for tires this wide), the bike feels like a racing bike. On gravel, I can go down to 22 psi (1.5 bar) without risking damage to the casings. I run them tubeless now, after suffering two pinch flats during the Otaki 100 km Mountain Bike Race in Japan (above). As I found out, riding over really rough ground at very high speed will pinch-flat even 54 mm tires!
I feel that for riding on rough gravel, tubeless really is the way to go. Choose tires that are wide enough, run them at low pressure, and you shouldn’t have trouble. (Unless your rims are way out of spec.)
For road riding, the advantages of tubeless tires are less clear. Pinch flats are much less of an issue on the road, unless you still ride ultra-narrow tires. All the testing I’ve seen – including our own – indicates that the rolling resistance of tubeless tires is no lower, and perhaps even higher, than using thin, lightweight inner tubes. That isn’t surprising: You replace an ultra-supple inner tube with a liquid sloshing around inside your tire.
What about flats? One nice feature is that the sealant inside the tubeless tire automatically seals small punctures. You don’t have to go tubeless for that: Some riders use sealant inside their tubes. They report that it also seals small punctures in the tube – provided you use it from the start, when you mount a new tire. (With an old tire, during a puncture, the air may not escape through hole that is right above the puncture in the tube, but through a bigger hole from a previous puncture that is elsewhere in the tire. Then the sealant flows into the space between tire and tube, creating a mess without sealing the tube.)
Based on all of the above, we – as well as other tire makers like Pirelli – have concluded that at this time, running high-pressure tires tubeless isn’t worth the risks. Can these issues be resolved? It’s difficult to say. Perhaps ‘Road Tubeless’ is the way of the future, or perhaps it’ll be like radial tires for bicycles. Cars have used radials for decades, but for bicycles, they never caught on.
What needs to happen to make tubeless tires safe even at high pressures? Clearly, the interface between tire bead and rim must become more standardized, and manufacturing tolerances must become tighter. With a ‘perfect’ rim, it’s already fine to run our 35 mm tires tubeless at 90 psi, but how do we get all rims to be perfect?

For now, here is the take-home message for running tubeless tires:

  • For tubeless, we recommend a maximum pressure of 60 psi (4 bar).
  • If you are riding on gravel or rough stuff, tubeless eliminates pinch flats. And you’ll be running less than 60 psi anyhow.
  • If you ride on the road and need more than 60 psi, use inner tubes. Not just with Compass tires, but with other brands as well.
  • Even on smooth roads, Compass’ wide tires roll as fast as our narrow ones. Getting wider tires and running them at pressures below 60 psi is a good way to use tubeless on the road.
  • When mounting a tire tubeless, first inflate it 20% higher than the pressure you’ll be riding. Let it sit for a while to make sure it will not blow off your rim. Then decrease the pressure before you ride the bike. That way, you know that you aren’t at the upper pressure limit for that particular tire/rim combination.

Tubeless technology holds great promise, but like everything, it should be applied where it makes sense and where it is safe. In a future post, we’ll talk about tips on how to set up Compass tires tubeless.
Photo credits: Nicola Joly (exploded tire), Cyclocross Magazine (damaged casing), Toru Kanazaki (Otaki 100 km Race)

Continue Reading

Tubeless-Compatible Barlow Pass 700C x 38 mm


First, I want to apologize that several Compass tire models are out of stock. Orders from our distributors in Europe and Japan have exceeded our expectations, and tire production has to be scheduled long in advance… The tires now are on a boat to Seattle. We should have all models back in stock toward the end of the month. Until then, we appreciate your patience. We’ll put up an announcement when the new tire shipment comes in.
That shipment also includes the new Barlow Pass tubeless-compatible tires. Not only did we change the bead to a tubeless-compatible one, but we also increased the size by 1.5 mm to make it a true 38 mm even on narrow rims. The photo above shows a prototype. Mounted with a tube on a narrow rim, it measures 37.5 mm. On a 30 mm-wide rim and mounted tubeless, it “grows” to 40 mm. That puts it right in the middle between our 35 mm Bon Jon Pass and the 44 mm Snoqualmie Pass. The new Barlow Pass is another great addition to the Compass range. If you want to run your tires tubeless, it’s definitely worth the wait.
Click here for more information about Compass tires.

Continue Reading

A True Dual-Purpose Knobby

steilacoom_paved
“Don’t do this on knobby tires!” would be most cyclists’ advice when looking at the photo above. Everybody knows that cornering hard on pavement and knobby tires don’t go together.
And yet, the photo shows me on Compass Steilacoom knobby tires. And I didn’t take any undue risks. It was a cold winter day, and the pavement was still moist from a recent snowfall, so I didn’t push the limits, and the tires always had plenty of grip in reserve. (I apologize for the blurry photo – there wasn’t enough light for high-speed photography on this dark winter day.)
We took this photo during an all-paved ride around Mercer Island – a fast-paced route with many corners and subtle (and not-so-subtle) ups and downs. It’s a challenging course to ride fast. And it’s even more challenging when riding with my friend Ryan, who trains here several times a week and knows every inch of the road.
I rode a bike with Compass 700C x 38 mm Steilacoom knobbies (above), because I wanted to find out how well they perform as dual-purpose tires.
steilacoom_action
After a full season of cyclocross, we already know the Steilacooms work great on mud and loose surfaces… What about rides that are mostly on pavement, but include enough muddy trails that you’d want some knobs on your tires?
I had always been bothered by how terrible my cross bike felt on the few paved sections of the race course. Those sections rarely measured more than a few meters, but if there was a corner, I had to take it carefully. Annoying when I really wanted to go all-out. I figured that there had to be a better way. And when designing the Steilacooms, we thought hard about how to make a knobby perform well on pavement, too.
steilacoom_on_pavement
How do you make knobbies that perform well on pavement? We designed the tread pattern together with the engineers at Panaracer. They were excited to bring all their knowledge to the project, with no concern about “what people expect a knobby tire to look like.” Together, we spent a lot of time thinking about knob shapes and spacing, and how the tire transitions from one knob to the next.
The key difference to previous knobbies is that we didn’t look at each knob individually. We treated them as a system that interacts, not just as the tire is rolling forward, but also as it leans into a turn. We made sure that there always is the same amount of rubber on the road, not sudden changes as you transition from one row of knobs to… sometimes almost almost no rubber at all.
We also discussed knob sizes with Panaracer’s engineers. They have to be small enough to dig into the mud, but large enough that they don’t fold over during hard cornering. It’s not rocket science, but it requires visualizing what the tire will do as it rolls and corners.
On the Steilacoom, you don’t fall off one knob and then climb onto the next, so the tires roll more smoothly than most knobbies. And the knobs are big enough that they don’t squirm, which also helps with your speed and cornering.
steilacoom_corner2
I had high expectations for the Steilacooms, but even I was surprised how well they perform on pavement. On that ride around Mercer Island, I had no trouble keeping up with Ryan, even though he was riding his new titanium bike with smooth Compass Babyshoe Pass Extralight tires. The Steilacoom knobbies did not just perform well on the straights, I also didn’t lose any ground in the corners. Of course, this doesn’t prove that the Steilacooms roll quite as well as the Babyshoes, but if there is a difference, it is much smaller than I anticipated.
During our next “BQ Team” ride, I switched bikes with Mark. At first, he was reluctant. “Why would I ride knobbies on the road?” he asked. But then he, too, was surprised. He said: “When you hear the knobs sing on the pavement, you think the bike will be slow. But on the downhills, the wind drowns out the tire noise, and then you realize that they perform pretty much like a good 38 mm road tire would.” And this from the guy who had sworn off knobbies for good when he designed his 650B randonneur bike.
Now, we understand that many readers will be skeptical when a maker claims that their new tire revolutionized how well a knobby tire rolls. So we took a few photos… with a little tree to show that we didn’t just tilt the photo to make it look more dramatic. The Steilacoom really raises the bar beyond what even we thought possible.
steilacoom_sx
The optimized arrangement of knobs is only part of the story. Just as important for the Steilacoom’s speed is the supple Compass casing. The result is a knobby tire that is faster than most slick road tires.
Are there drawbacks of the Steilacoom tread pattern? Of course, otherwise, we’d all ride knobbies from now on. First, once we test them on the track with a power meter, I fully expect that they will roll a little bit slower than our other tires. That is unavoidable, but the difference is too small to notice on the road. That is pretty remarkable.
The knobs also add weight to the tire. And the bigger you make the knobs, the heavier the tire gets. Thanks to our lightweight casings, the Steilacoom still isn’t a heavy tire, but it weighs about 30 g more than our Barlow Pass with smooth tread. This won’t slow you down much even when climbing mountain passes, but if you don’t need knobs, why carry the extra weight?
Like all knobbies, the Steilacooms tend to wander a bit while going straight. You are rolling from one knob to another, rather than on a continuous tread. Again, it’s not a huge deal, but if your ride doesn’t require knobbies, I would pick one of the other Compass tires with their road-optimized tread. And finally, there is more noise from the tires as they roll. But compared to other knobbies I have ridden, all these disadvantages are very subdued.
naches_highland
The Steilacoom’s excellent pavement performance opens up completely new rides. Imagine you are heading into the mountains and expect muddy sections along your course, but most of the ride will be paved. No problem with the Steilacooms. They will make short work of the mud, without holding you back on the paved portions of your ride. That makes the Steilacoom the ultimate multi-purpose tire.
Click here to find out more about the Steilacoom 700C x 38 mm tires.
Photo credits: Ryan Hamilton (Photo 1, 4), Heidi Franz (Photo 2), Duncan Smith (Photo 5), Hahn Rossman (Photo 6).

Continue Reading

Panaracer: Hand-Made Tires


A highlight of my visits to Japan is going to the Panaracer factory. It’s a magical place, where some of the world’s best tires are made largely by hand. It resembles a storybook factory: Huge machines emit hissing steam. Skilled hands assemble casing, beads and tread. Hot tires cool as they move along conveyors under the roof.

The main reason for my visits to the factory is to discuss ideas for new tires, and improvements to existing ones, with Panaracer’s engineers (above). These guys know more about making bicycle tires than almost anybody in the world. We bring them our ideas, they provide feedback and input, and together, we finalize new designs, like the innovative tread pattern of our Steilacoom knobbies.
During recent meetings, we’ve been talking a lot about tubeless tires. Tubeless is an emerging technology without real standards yet. We must figure out how to make tires that work on as many different rims as possible. When customers have problems, we try to diagnose and troubleshoot for them. We all share the goal of making the most of this exciting new technology.

Once we have finished our meetings, we often get to walk around the factory. Two weeks ago, we saw our Steilacoom, Switchback Hill and Snoqualmie Pass tires being made. It was the first time that my visit coincided with one of our production runs – great fun!
There is nothing really toxic involved in making tires at this factory – just steam and heat – so there is no need for protective clothing, not even earplugs. (Like many Japanese, the worker below wears a face mask for protection against spring-time pollen, not industrial pollution.)

Making tires starts with kneading the hot tread rubber in huge machines that look like they belong in a giant bakery. The rubber is rolled into thinner and thinner strips, until it has the right thickness for the tread.

The casing is stored in huge rolls, ready to be impregnated with rubber. Both the thickness of the threads and the amount of rubber coating determine how supple the tire will be. This is where the experienced workforce and time-tested machinery allows Panaracer to go a few steps further than most tire makers and use ultra-fine fabric and a very thin rubber coating to make the lightest and most supple tires possible.

The tires are assembled by hand. It’s a fascinating process, and I could easily spend a month photographing the factory. There is enough material write a book! But there are too many trade secrets, so no photography is allowed. Panaracer’s engineers would prefer if nobody knew what is going on in their factory.
Ever since I first visited this amazing factory, I’ve wanted to show our readers how high-end tires are made. It took us years to persuade the company to do a photoshoot last year. Each photo was carefully vetted before it was cleared for publication in Bicycle Quarterly. Knowing this, I feel incredibly privileged to be allowed to see everything and ask questions about anything when I am visiting.
Once assembled, the raw tires look almost like the finished product (above), but they are only loosely assembled. They still lack their tread pattern, too. All this comes in the next, most impressive step…

Each tire is vulcanized (above). That means it is placed in a mold that is engraved with the tread pattern. Steam heats the mold until the rubber partially melts. The tread rubber flows into the mold and is imprinted with the tread pattern. Since the tire partially melts, all its elements are fused together and become inseparable, making the tire very strong. When the tire emerges from the mold, it is no longer flat, but has the domed shape of, well, a tire. After it cools, it’s ready for quality control and packaging.
In the past, vulcanized tires were considered slow, and hand-glued ones were faster. That was because the casing material used in the factories that vulcanized their tires was stiff and not optimized for performance. With all tires, the casing is by far the most important factor that determines the tire’s performance and comfort.
Panaracer’s high-end tires use very supple casings, yet they are vulcanized. This combines the best of both worlds – the naturally round shape of the tire further optimizes the tires’ performance: As the wheel rotates and the contact patch leaves the ground, the tire automatically resumes its round shape.
Many hand-made tires are not vulcanized. Held together with strong glue, they look like the raw tires in the photo above – flat. When their contact patches leave the ground, tire pressure has to overcome the tire’s natural flat shape to make it round again. According to Bicycle Quarterly‘s testing, this makes the tire about 3% slower.(1) The very best tubular tires, such as those made by FMB, are assembled on an inflated casing. That way, the tire has the same round shape as a vulcanized tire. Why aren’t all tires vulcanized? Small makers don’t have the machinery that is required.

For the Compass Extralight models, Panaracer uses a casing usually reserved for their top-end racing tubulars. Panaracer doesn’t use this casing on their own clinchers. The company feels that their tires may end up with inexperienced customers, who may need sturdier tires.
We are glad that Panaracer’s engineers are willing to push the envelope a bit further for our Compass tires. We are confident that Compass customers try to avoid crashing into potholes and obstacles that could ruin a high-performance tire. In any case, the limits of what supple tires can do are quite high – witness the photo above showing a set of Compass Extralight tires in action. The tires survived the long and rough descent from Odarumi Pass in Japan without damage.
I cannot show you the factory, but if you are going to the North American Handmade Bicycle Show (NAHBS) in Salt Lake City, Utah, this weekend, you’ll be able to meet the people from Panaracer. Stop by their booth and tell them how much you enjoy the tires they make for us!
The full report on the Panaracer factory was published in Bicycle Quarterly 58. If you missed that issue, it’s available as an individual back issue or with our 4-pack of the last year’s Bicycle Quarterlies.
Click here for more information about Compass tires.
(1) We tested two tires made with the same casing and tread. One was assembled on an inflated casing, the other “flat-glued”.

Continue Reading

When to Use Knobby Tires

hahn_tree_fb
Compass has long championed the use of “road” tires on gravel. More and more gravel racers agree: When gravel is sliding on gravel, knobbies are of little use.
So then why does Compass offer a knobby tire, the Steilacoom 700C x 38 mm? Knobs are useful in mud. They dig into the surface, and since the mud is viscous (gooey), it provides something for the knobs to push against. That is why cyclocross bikes use knobby tires.
700x38cx_mud
It’s important is to space the knobs widely, so the mud is ejected as the tire rotates. Otherwise, the tire just clogs up, and soon you are riding on slick tires again, except that their tread is made of mud instead of rubber. What you want is a muddy bike, but clean tires (above) – the tires pick up mud only briefly before it is flung off.
snow_walupt
Snow is a different story again. Depending on your speed, it behaves differently. At high speeds, you glide through the snow almost as if you were skiing, and tread patterns make little difference. At low speeds, you compact the snow and create the surface on which you ride. Knobs dig into that surface and give you extra grip. Even a herringbone tread works OK. Slick tires or longitudinal ribs act like the runners of a sled – they just slide and offer very little traction.
testing_ice
What about ice? Ice is too hard for rubber tread to dig into. You need metal studs that bore into the ice to find traction. Sometimes, snow compacts to ice (above). I prefer to walk rather than risk a fall when I see ice on the road. (Unfortunately, I don’t know of a good method to see “black ice” before it’s too late.)
fmb_super_mud
Back to mud, where knobbies make the biggest difference: Designing a good mud tire isn’t hard – space your knobs widely, and the tire will self-clean as it rotates. The downside is that it’ll be buzzy and slow on pavement. I love the FMB Super Mud tires (above) on my old ‘cross bike (our Steilacooms don’t fit!), but their secret isn’t in the tread pattern – the extra-supple casing makes them wonderfully fast and contributes to their great traction. The tread is incredibly buzzy on pavement. It’s good that most ‘cross courses include no more than a few meters on pavement.
The knob shape itself makes little difference. “It’s all about ‘design'” a Panaracer engineer confided.
dual_purpose_tireDesigning a knobby tire that rolls OK on pavement is not too hard, either. Space your knobs closely, and the tire will roll fine. But when it gets muddy, the tire will clog up, depriving you of the advantages of a knobby tire. You get only the disadvantages of knobbies, without many of the benefits.
steilacoom_testing
Designing a tire that rolls well on pavement and grips well in mud is much harder. If you also want the tire to corner well without knobs folding over and suddenly losing traction, it seems almost impossible. And yet… with the engineers at Panaracer, we spent a lot of time analyzing and testing knob designs during the development of our Compass Steilacoom 700C x 38 mm knobbies. We found a few things that can greatly improve a knobby’s performance on pavement, without detracting from its ability in mud. More about that in a future post…
Click here for more information about Compass tires.
Photo credit: Wade Schultz (bottom photo)

Continue Reading

Why We Don't Make "Gravel" Tires

pub_compass_mexico
At Compass Cycles, we love riding on gravel roads, so it may come as a surprise that we don’t make “gravel” tires. Compass tires are road tires, perfected for use on paved roads. The rubber compound is optimized for grip on pavement, and the “chevron” tread pattern interlocks further with the road surface. Everything about our tires is optimized for performance, both in a straight line and around corners, in dry and wet conditions.
switchback_hill
So why do gravel racers love our tires? Because they are supple and ultra-fast. What about the “road” tread? Wouldn’t you want knobbies for riding fast on gravel?
The truth is that on gravel, knobs don’t make any difference. Without semi-firm ground to dig into, knobs can’t do anything. When you slide, it’s because gravel is sliding on gravel, not because your tires are sliding on the top layer of rocks.
quattro_slicks
Rally drivers made a similar experience. During the early 1980s, they found that, to their surprise, the slick tires they used on the paved roads were faster on gravel than tires with more tread (above). Even though slick tires aren’t allowed on rally cars any longer for a variety of reasons, the lesson may remain valid: On gravel, tread patterns make little difference.
For bicycles, what makes a good road tire also makes a good gravel tire:

  • Supple casing: on the road, this gives you speed and comfort. On gravel, the same still holds true, but it also gives you traction, because the tire conforms to the surface, and thus has more grip. (One advantage of the rally cars’ slick tires was that they were super-soft.)
  • Large width: On smooth roads, more air just means more comfort. On rough roads and gravel, it also means more speed, because your bike doesn’t bounce (which loses energy through suspension losses).

The same features that make our tires perform so well on pavement also make them great on gravel. We’ve resisted the temptation to add knobs for a more “rugged” appearance. Instead, Compass tires offer you the best performance on a variety of surfaces. That is why we call them “Allroad” tires.
If knobbies don’t help on gravel, why does Compass now offer a knobby tire?
steilacoom_sx
The answer is simple: mud. When it’s muddy, knobs dig into the surface. You get more traction, because a knobby tire needs to displace much more material to spin. We designed our Steilacoom knobbies to offer good performance on pavement, too. In fact, first tests show that they are faster than any knobby we’ve tested, but they’ll never equal the performance of our “Allroad” tires.
elk_pass_gravel
What about flats? Shouldn’t a gravel tire be reinforced to fend off flats?
It depends. Punctures are less likely on gravel, because the tire pushes sharp objects into the (relatively soft) ground. On pavement, the hard road surface forces the object into the tire. That is why punctures from glass or nails are rare on gravel.
Sidewall cuts from sharp-edged rocks can be a problem for some riders, and many “gravel” tires have reinforced sidewalls. But that also makes them slower, less comfortable, and reduces their traction. Cyclocross racers have ridden on high-end tubulars with very supple (and unprotected) sidewalls for decades. And many gravel racers use Compass tires without suffering from cuts. It really depends on your riding style – experienced cyclists usually ride “light” and let the bike move under them. They usually suffer from few problems. Tire pressure also plays a role. If the pressure is too high, it’s easier to damage the sidewall. A softer sidewall deflects as it hits a sharp rock rather than getting cut.
dirt_road
Just before winter snow closed my favorite roads last November, I was heading into the Cascades to explore gravel roads on a 700C test bike for Bicycle Quarterly. As I set up the bike for this challenging ride, I had to choose betweeen knobbies and road tires. My decision was easy: Road tires roll much better on the paved portions of the ride, while giving up nothing on gravel. They were an obvious choice.
But now I am plotting a truly muddy ride, so I can take our new Steilacoom knobbies for an adventure, rather than using them only for cyclocross…
Click here for more information about Compass tires.
Addition (2/21/2017): Several rally experts have questioned whether early-1980s rally cars used slick tires on gravel. At the time, it was reported in the German magazine Auto, Motor & Sport, but the use of slick tires on gravel may just have been isolated to a few rallies. Shortly after that report, the rules of rallying changed, and slick tires no longer were permitted, either on gravel or pavement.

Continue Reading

Steilacoom Tire Testing

surch_pack
We thoroughly test every Compass product before we release it. We also seek unbiased evaluations from experienced riders who weren’t involved in the development of the products. For the new Compass Steilacoom cyclocross tires, we gave them to a number of cyclocross and gravel racers. Two of them have reported back in detail, and we are happy that they like the new tires even more than we do. Matt Surch (above) is one of the fastest gravel racers in Ontario. Wade Schultz (below) is a Category 2 ‘cross racer from Seattle.
remount
Both liked the performance on damp surfaces and mud – Matt commented: “The grip is fantastic, allowing extreme lean angles” – but that was to be expected on a tire with big, widely spaced knobs. What surprised them both was the excellent performance on pavement.
surch_pavement
Wade: I expected these tires to be appropriately slow on smooth pavement, but was frankly surprised by how well they did. Their rolling resistance is lower than other pure mud CX tires (tight center knob spacing helps). I love the excellent transition from center to side-knobs. I did not experience any on/off traction vagary on corner lean initiation.
Matt: My Woven rims have a very good tubeless bead shelf and inner ridge that holds the bead in place. They mounted easily, and I went out for a cx rip. Wow! Seriously, I didn’t expect this tread to roll so well. Yes, it’s pretty close to linked in the centre, but with so much open space, I thought they’d feel slow on pavement. Nope. Instead, they just feel like they roll sort of crazy fast, like faster than they should.
This isn’t a complete surprise – much thought and development went into the spacing of the knobs. We didn’t want to space them so close that they’d clog up and no longer grip on mud, but we alternated them in a way that keeps the tire supported, rather than have it bump up and down as the knobs pass underneath.
surch_sand
The other question is what tire pressure is ideal for these tires? Matt tested the absolute minimum he could run:
Matt: I took pressure down to 27, which was low enough to fold the rear on off cambers and fold the front on some soft to hard transitions. This is the same sort of folding I’d expect from my tubulars, and I figure if I can get a tubeless tire to fold but not burp, I’m good. I lost no pressure at all after 40 minutes of trying to get them to burp. And this is minutes after mounting.
A minor note of caution: Running your tires at pressures this low gives you the ultimate in traction for cyclocross racing, but it can reduce the life expectancy of the tires, as the casings are under a lot of stress when they fold over.
matt_off_camber
Matt raced the tires in the first races of the season. He reported after the first one:
Matt: My experience through the 60 minutes of racing was overwhelmingly positive. I didn’t feel at 100% physically at the start, yet I had my best cx race I can remember, finishing closer to a few adversaries than ever before, for 4th overall in the Senior / Master 1 race.
wade_woodland
It’s exciting that the tires work as well as we had hoped. A lot of thought went into that tread design – it’s much more than just a few widely spaced knobs – and we are glad that the tires offer the on-pavement speed and smooth cornering that we wanted to achieve. Here are the final words from these two experienced racers:
Wade: Is my satisfaction with this tire linked more directly to the casing volume (vs traditional cx tubulars) or the tread design? [I suspect the answer is: Both.]
Matt: I am extremely happy with them. Congrats on making an awesome tire.
Further info:

Photo credits: Andrea Emery (Photos 1, 4, 5); Heidi Franz (Photos 2, 6) Alain Villeneuve (Photo 3).

Continue Reading

New Compass Tires: Naches and Snoqualmie Pass

snqualmie_pass_800
Compass Cycles is introducing two new models to its tire line. We’ve had many requests for 700C and 26″ versions of our iconic 650B Babyshoe Pass tires. Here they are!
We’ve added 2 mm to the width, because we found that 44 mm-wide tires will fit most bikes designed for wide 700C and 26″ tires. As with all our tires, we named them after the places that inspired them.
snoqualmie_pass
Most cyclists cross Snoqualmie Pass on the “Iron Horse Trail” that uses an old railroad right-of-way. Back in the day, the Milwaukee Railroad’s Olympian Hiawatha raced across the Cascades here. Today, it’s a trail that is covered with loose gravel in places. High-volume tires are key to an enjoyable ride here. Traversing the 2.3-mile tunnel right on the pass is an exciting part of the adventure.
00005150
The original Hiawatha trains were the fastest in the world – their streamlined locomotives were easily capable of 124 mph (200 km/h).* As befits a train named after an Indian legend “so fleet of foot” that he could outrun an arrow shot from his own bow. It’s nice to think of our tires in these terms: They are among the fastest in the world.
naches_pass_rectangle
Our tires are not just “fleet of foot”, but also intended for some pretty rough “roads”. Naches Pass is one of the “secret passes” that cross the Cascades. The new Compass Naches Pass tires measure 26″ x 1.8″ (44 – 559 mm), making them perfect for many touring bikes with 26″ tires. Wouldn’t it be wonderful to chart an alternative cross-country route using only little-known byways, starting with Naches Pass. I am tempted…
naches_pass_tire
The Naches Pass also is a great tire for small bikes, where 650B wheels make it difficult to avoid toe overlap and other design compromises. The nice thing is that you all the parts designed for 650B bikes fit 26″ tires as well: Compass centerpull brakes and rack, fork crown, etc. It’s a great way to go on a smaller frame.
The new tires are tubeless-compatabile. As with most of our tires, they come in several versions:

  • Standard casing: a supple casing that offers excellent durability and cut resistance. Available with tan sidewalls.
  • Extralight casing: an extra-supple casing usually reserved for hand-made tubulars. Compass Extralight tires offer the ultimate in performance and shock absorption. Available with tan or black sidewalls.

Click here for more information about Compass tires.
* Note: The Olympian Hiawatha apparently did not use the streamlined locomotives, and it certainly never reached 200 km/h. Those speeds were achieved on flatter routes in the Midwest.

Continue Reading

Transcontinental Race on Compass Tires

albula
Congratulations to Andreas Behrens of LaFraise Cycles for completing the amazing Transcontinental Race. Riding unsupported for almost 2,400 miles (3900 km) over a course that traversed all of Europe, Andreas completed the non-stop race in 15 days and 12 hours.
xyz123
The course traversed the highest mountain ranges of Europe – above the view from the Grimsel Pass to the Furka Pass in Switzerland. All in all, Andreas climbed more than 40,000 m (130,000 ft).
la_fraise_transconti
Andreas builds bikes himself. The one he rode in the Transcontinental Race was equipped with Compass Loup Loup Pass Extralight 650B x 38 mm tires. After the finish, he sent us photos of his tires:
front_tire
Even after 4000 km, the front tire still has plenty of life left.
rear_tire
The rear tire is a bit more worn. The wear is almost entirely in the center of the tread – an indication that Andreas is running slightly higher tire pressures than we’d recommend. He might be more comfortable and even faster if he let out a tiny bit of air.
bosporus
When he dipped his wheels into the Dardanelles at the finish in Turkey, he hadn’t suffered a single flat tire!
Andreas isn’t a sponsored rider – he bought the tires with his own money. I asked him why he chose Compass tires. His response:
“I have a few bikes with wider tires, between 32 and 42 mm. From experience, I knew that on these bikes, I wasn’t any slower than other riders on their racing bikes. In the past, the tires from Panaracer and Grand Bois always felt a bit stiff. When I visited JP  at 2-11 Cycles [Compass’ French importer], I had the opportunity to test the Compass tires. I liked the ride very much and decided to use the 38 mm version on my bike for the Transcontinental Race.
“Of course, it also was a test to see whether the Compass tires would survive the race. I only recommend products to my customers that I use myself. My experience confirms your testing: the tires reduce vibrations and fatigue. Of course, it wasn’t only the tires: The steel frame, custom geometry, comfortable saddle and ergonomic handlebars helped me finish the race without soreness or injury. No saddle problems, no numb hands, even though I mostly rode without gloves. I credit the comfort of the bike.”
control_card
Riding from Belgium to Turkey, all the way across Europe, without any major aches and pains – that is truly inspirational. Congratulations!
Click here for information on Andreas’ bikes: LaFraise Cycles.
Photo credits: Andreas Behrens (LaFraise Cycles).

Continue Reading

Steilacoom: Our First Cyclocross Tire

steilacoom_action
It’s no secret that we love cyclocross. It was only a matter of time until Compass Cycles would introduce a ‘cross tire. Like all our products, the new Steilacoom fills a need that currently isn’t being met: a supple, wide ‘cross clincher that is tubeless-ready and that approaches the ride and performance of my beloved FMB ‘Super Mud’ tubulars.
The Steilacoom is named after an iconic ‘cross course near Seattle. It’s where I won my first cyclocross race on a course that (back then) featured a daunting descent and a brutal run-up. What makes the new Compass tire special is its width: 38 mm is wider than most ‘cross tires.
steilacoom_sx
Some will argue that the UCI limits ‘cross tires to 33 mm. True, but most of us don’t race in UCI-sanctioned categories. In the U.S., this rule appears to apply only to the national championships. If you are competing at that level, you probably already have a bunch of FMB or Dugast tubulars and expensive wheels to glue them onto. For the rest of us, the UCI rule is irrelevant, yet most ‘cross tires are limited to a maximum width of 33 mm. If you ride clinchers, this is less than optimal.
To provide the same traction and comfort, a clincher needs to be about 10-15% wider than an equivalent tubular. Scaling up a 33 mm tubular gets you a 38 mm clincher. This tire still fits into most current cyclocross frames – no need to go ‘monster-cross’ to fit the new Steilacoom tires.
The Steilacoom ‘cross tires are available with our Extralight casing that usually is used for handmade tubulars. It’s one of the best, fastest-rolling casings anywhere. For those on a budget or with a propensity to cut their tire sidewalls, we also offer them with the Standard casing that still offers superb performance. The Steilacoom tires are tubeless-compatible – that is, they are designed to be used with tubeless rims and sealant. Of course, you also can set them up with tubes.
cross_nats_96
What about the tread pattern? It’s based on more than 20 years of experience racing cyclocross. The 1996 newspaper article above shows me at the very first collegiate cyclocross nationals ever held in the U.S., with my Alan – the bike I still race today.
WOLBERCROSSSUPERXSP1
Back then, cyclocross tires were quite simple: The best ones used a tread pattern that consisted of round knobs. Key was to have them spaced widely enough so that they didn’t clog up with mud. Traction was great – I just wish they had been wider than the 25 mm or so that they measured. (It’s incredible that back then, we raced ‘cross on tires as wide as those that the pros use today on the smooth roads of the Tour de France!)
When I discussed tread patterns with the engineers from Panaracer, their opinion was succinct: “With knob shapes, it’s mostly about fashion.” I thought about that and realized that the old round knobs made a lot of sense: You don’t want the tread to clog up with mud, so the fewer edges you have, the harder it is for the mud to stick to the tire. A round knob has the smallest surface area for mud to stick.
steilacoom_testing
Panaracer’s engineers cautioned that round knobs might slide through the mud too easily. A straight edge provides more traction. That is why our knobs are square, with rounded corners. That way, the knobs present straight edges for the forces of pedaling and braking (front/back), as well as cornering (right/left). It’s logical.
What matters more than the knob shape is their size and especially their pattern on the tire. We placed the knobs so that there are a few more in the center. The square knobs are harder to deform than thinner, irregular shaped ones. This reduces the squirm on hard surfaces. The knobs are placed so that the transition from the center tread to the shoulders is smooth and gradual. The slightly larger shoulder knobs resist squirm during hard cornering. That way, the tire rolls smoother and corners better on hard-packed dirt and pavement. The first rides by cyclocross racers have confirmed this: On pavement, the Steilacoom exhibits none of the sudden breakaway that you get with most other knobbies. Many riders will want to use these tires for mixed-surface rides where they expect significant mud.
What has been most surprising during our testing of the prototype Steilacooms is how well the new tires roll and corner on pavement. We always intended the tire as a dual-purpose tire that excels on all surfaces, paved or not, but we weren’t sure whether it was possible to create a knobby that excels on pavement, too. At the same time, they shed mud like my FMB ‘Super Muds,’ which is about the highest benchmark we can imagine. The ride is as great as you’d expect from our supple casings, and the knob pattern delivers on its promises.
cross_race
I can’t wait to race on them. I have a (slightly) more modern Alan with clearance for tires this wide. Now I just have to build it up with a set of tubeless rims!
Click here for more information about the new Steilacoom tires.
Photo credits: Heidi Franz (top); Wade Schultz (second from bottom), Leander Vandefen (bottom).

Continue Reading

Minimum Tire Pressure

Hahn_Paso

Over the last few years, the idea that higher pressures don’t make your bike faster finally has become accepted. Many cyclists now run lower pressures to improve comfort and traction, without giving up anything in speed.

On gravel, lower pressures actually make you faster, since the bike bounces less. On soft gravel, like we encountered during our ride across the Paso de Cortés in Mexico (above), lower pressures (and wider tires) allow you to float on top of the surface, rather than sink in. Again, that makes you faster and more secure.

So lower pressure is better in many cases, but how low can you go?

contact_patch

Here is a detail from the photo of Hahn on the Paso de Cortés. You can see how long that contact patch is – there is a lot of tire on the ground, which spreads the rider’s weight over a larger surface area.

Yet the pressure is not too low. The tire still holds its shape: Seen from the side, the tire sidewalls form a nice circle. That is the reason why it still rolls as fast as it did at higher pressures: The flex in the tire is limited to a relatively small area.

Only when viewed from above, can you see the contact patch bulge outward – but even that should not be excessive.

paso_cortes_descent

What happens if your tire pressure is too low?

  1. The tire can collapse when cornering. During our Mexican adventure, we pumped up our tires when we reached pavement, so we could tackle the fast and twisty descent with confidence (above). Even on gravel, a tire can collapse under the forces of cornering, if it’s not inflated high enough.
  2. You can pinch-flat, if the tire bottoms out, and the tube gets crushed between rim and road surface.

BJPASS_result-750x481

3. The tire can get damaged. When the tire gets kneaded too much with each revolution, it’s not only slower. (Yes, lower pressures do get slower at some point.) It also puts very high stresses on individual threads of the casing, which then can break. The tire needs a certain pressure to hold its shape and distribute the stresses uniformly over all the threads in the casing.

In the photo above, you can see a cross-hatched pattern where the casing threads have broken. This tire was tested by a magazine, and they rode these 35 mm tires at extremly low presssures of just 35 psi (2.4 bar).

The tire probably is still fine to ride, but if you try to run it tubeless, air (and sealant) will seep out of the tiny holes caused by the broken threads. (The sealant colored the sidewall where it leaked.) If you see a single zigzagging line in the tire sidewall where one thread has broken, increase your air pressure slightly to prevent further damage.

What is the minimum pressure that is OK to ride?
This depends on many factors, including:

  • Rider weight. Obviously, heavier riders need to run higher pressures to prevent the tires from collapsing.
  • Surface grip: The more grip you have, the higher are the forces generated during cornering. To withstand those forces, your tire needs to be inflated harder.
  • Tire construction: A stiff tire is held up by its sidewalls as much as by the air pressure inside. A supple tire’s sidewalls do little to support the bike’s weight, so you need higher pressure. Thanks to the supple sidewalls, this tire still is more comfortable and faster, even at the higher pressure.
  • Riding style: A rider who has a round spin can run lower pressures. If your bike starts to bob up and down with each pedal stroke, your tire pressure is too low. Fast riders need to run slightly higher pressures, since they hit obstacles with more force. And riders who corner on the limit need higher pressures to prevent the tire sidewalls from collapsing.

I polled the riders on the Bicycle Quarterly team about the tire pressures they ride. I was surprised how consistent they are. Some riders are a bit heavier and use a bit more air, so we equalized the values for weight of 82 kg / 180 lb.
tire_pressure_chart_psi

Or if you prefer metric values:

tire_pressure_chart_bar
Of course, we’ll adjust these values if needed, for example, on rough gravel, we increase the pressure to prevent pinch flats… And remember that different pressure gauges can vary by up to 15%, so your 45 psi may be quite different from our 45 psi! Still, this provides a starting point for thinking about the right tire pressure.
For the majority of riders today, the advice “When in doubt, let out some air!” still holds true, but as we lower our tire pressures, we need to be aware that too little air also can cause problems.
Further reading:

Photo credit: Cyclocross magazine (damaged casing)

Continue Reading

Panel Discussion: The Wide Tire Revolution

cyclingtips
“Buy the nicest, most supple tires you can afford; and buy them in the widest width that you can fit in your frame.”
That is Joshua Poertner’s summary of a panel discussion on Cyclingtips.com. Joshua used to be the president of Zipp, the makers of super-fast aero wheels, and he did a lot of research on how to make your bike faster.
The panel included Joshua, cycling journalist James Huang, and me, with Elden Nelson (who runs the blog “The Fat Cyclist”) moderating. The goal was to explain the science behind the current trend toward wider tires to an audience of racers and performance riders, who want to understand how to make their bikes faster.
In the podcast, we talk about why narrow tires feel faster, but aren’t. We discuss how lower pressures increase the internal resistance as the tire flexes, but decrease the suspension losses from the vibrations of the bike – the two effects cancel each other, hence your speed doesn’t change.
We also talk about the history of this research. I was amazed to find out that Zipp had been doing similar research to our own. They were trying to optimize tire pressures for the professional racers they sponsored. During their testing on rough surfaces like the cobbles of Paris-Roubaix, lowering tire pressure made their racers faster – until their wheels broke. The next step was to go to wider tires, so the wheels could survive… And then they found that even on smooth roads, lower pressures and wider tires were faster. They considered these findings “trade secrets”, and yet the other teams just had to read Bicycle Quarterly to get the same information. And eventually they did…
To me, Joshua’s conclusion really is remarkable: “Buy the most supple and widest tire you can fit in your frame.” His words could just as well have been mine. To have the guy who designed wheels for Zipp say this… It shows that the wide tire revolution has reached cycling’s mainstream.
Click here to listen to the entire podcast.
cyclingtips

Continue Reading

The Missing Piece: Suspension Losses

old_road_to_mexico

How does it work that wide tires are as fast as narrow ones? It is really simple:

Comfort = Speed

When your bike vibrates, energy is dissipated as friction. That energy must come from somewhere – it no longer is available to propel the bike forward, so your bike slows down. That is why your bike rolls faster on smooth pavement than on rough chipseal.

At Bicycle Quarterly, we started testing tires on real roads, with a real rider, in 2006. We found that higher tire pressures don’t make your bike faster. Back then, that was pretty revolutionary. Previous tests on smooth drums had shown that the harder you pumped up your tires, the faster you went. But smooth steel drums aren’t a good model for what happens on real roads, and the results were misleading.

Over the last couple of years, our findings have become generally accepted. Most tech writers now talk about vibrations that slow down your bike. The missing piece is: How do vibrations slow you down? The most common explanation is that your bike goes up and down as it vibrates. All that climbing adds up and costs a lot of energy.

It’s true that vibrations slow you down, but it’s a bit more complicated. Energy cannot disappear. The only way to ‘lose’ energy is to convert it to heat through friction. When you climb a mountain pass, you put in energy as you gain elevation. As you descend on the other side, you get some of it back – you can coast downhill without pedaling – but most of it is converted to heat by your wind resistance. During the descent, your bike accelerates until you reach ‘terminal velocity,’ where the energy input from the elevation loss equals the energy consumed by wind resistance.

That explains where the energy goes when you cross a mountain pass. It cannot explain what happens when your bike vibrates on flat roads.

RumbleStrip

We tested various equipment on rumble strips to get a maximum value for the energy that is lost to vibrations. We found that riding on this “very rough” road can take up to 290 Watt more power than riding on smooth pavement at the same speed. So it’s true, vibrations can absorb a huge amount of energy. It was almost impossible to keep the bike moving at our testing speed on the “very rough” road. (Of course, in real life, you don’t ride on rumble strips, but the point was to see how much energy could be lost just by changing the surface roughness, and keeping everything else the same.)

Since we were going at the same speed as on the smooth pavement, the our wind resistance was the same, and yet we had to push the pedals with 290 Watts more. So where did all the energy go?

basketball

A little bit went into heating the tire as it flexes, but pneumatic tires don’t absorb much energy even when they bounce. Think of a basketball. When you drop it, it bounces back almost as high as before. Very little energy is lost, even though it deflects as it hits the ground. As the basketball hits the ground, it compresses and becomes an air spring. Then it stops, before it starts accelerating upward again. The ‘spring’ in the ball returns most of the energy, and the ball bounces almost as high as it did with the last bounce.

tire_push_off_2

Tires work the same way. When a tire hits a bump (left), it deforms (arrow). Energy is stored – the tire becomes a compressed spring. On the other side of the bump (right), the energy is released, pushing the tire off the bump. The net loss of energy is small.

If the energy isn’t lost in the tire, then where does it go?

rough_road

The answer is simple: As the rider’s body vibrates, the tissues (muscles, tendons, skin, etc.) rub against each other. This can convert an enormous amount of energy into heat. How much? In a study of vibrating tank seats, the U.S. Army found that up to 2000 Watt were absorbed by a human body before the vibrations became too painful to endure. The discomfort was directly proportional to the energy loss.

2000 Watt! That is more than the power output of a pro racer. Clearly, a lot of energy can be lost due to these vibrations. The technical term for this is “suspension loss”. It also occurs in shock absorbers of cars – rally cars’ shock absorbers absorb so much energy that they get hot – so hot that they need dedicated cooling.

rumble_smooth

We also tested different types of equipment on the new, super-smooth pavement next to the rumble strips. We were surprised that even on very smooth pavement, reducing vibrations through supple tires – and even, to a lesser degree, a suspension fork – resulted in significant performance gains.

What this means for cyclists is simple: If your bike’s vibrations are uncomfortable, it’s because energy is converted into heat, inside your body. This energy is lost from the forward motion of the bike. As far as vibrations are concerned, being uncomfortable slows you down. Or seen the other way around, the more comfortable your bike is, the less power goes to suspension losses, and the more power is available to drive it forward:

Comfort = Speed

It really is that simple. And it’s revolutionized how we think about bikes: Wide, supple tires are faster because they vibrate less. Fork blades that absorb road shocks – even suspension forks – are faster, not just on rough roads, but even on relatively smooth roads, because they reduce vibrations. On real roads and at the speeds most of us ride (<25 mph), the best gravel and all-road bikes actually are faster than their racing bike cousins.

diverge_skagit

This means that the biggest improvement in your bike’s performance comes from a set of wide, supple tires. “Supple” means that the casing is thin and easy to flex. This has two benefits:

  1. Supple tires are easy to flex, so they transmit fewer vibrations (lower suspension losses). That is Reason 1 why they are faster.
  2. Supple tires are easy to flex, so it takes less energy as they deform them as they rotate (lower hysteretic losses in the tire casing itself). Reason 2 why they are faster.

Wide tires also transmit fewer vibrations, which makes them faster than narrower ones.
Our testing shows that supple casings are more important than width. A supple 26 mm tire is much faster (and more comfortable) than a stiff 38 mm “touring” tire. Of course, ideally, you’ll get it all – a wide and supple tire.

This research led us to develop our Rene Herse tires. While quite a few makers offered supple racing tires in widths up to 25 mm, there weren’t (and still aren’t) many great high-performance tires in wider widths.

For our Extralight series, we use a casing that usually is reserved for high-end, hand-made racing tubulars. On top goes a layer of extra-grippy, yet long-wearing, rubber with our trademark tread pattern that interlocks with the road surface for extra grip. The result are our Rene Herse tires – available in widths from 26 mm to 55 mm.

tekne_gravel

Before releasing these tires in 2014, we tested them extensively on some of the roughest gravel roads to ensure they were durable enough for real-world riding. Since then, they’ve proven themselves in gravel races, but also on paved courses like Paris-Brest-Paris. They even took second place in the Washington State Road Racing Championships. The riders who use them are our best advertisers, recommending them to everybody who is willing to listen. We rarely advertise – instead, we focus on new research that will improve our products even further.

Further reading:

Photo credit (gravel racing): Chyla’s Race Photos.

Continue Reading

Rat Trap Pass back in stock

rat_trap
This is just a quick note that our popular 26″ x 2.3″ Rat Trap Pass tires are back in stock in all versions. We’ve been surprised by the popularity of these tires…
Many cyclists have a cherished old mountain bike, an expedition tourer or a tandem that is transformed with a set of supple high-performance tires. Others had Enduro Allroad bikes custom-built around these tires. In fact, I’ve been riding the Rat Trap Pass myself, and all that volume and speed is almost intoxicating.
elk_pass
At the other end of the 26″ tire spectrum is our Elk Pass 1.25″ tire. It’s one of the lightest, fastest 26″ tires ever made, and many riders rave about them. Here is what Georgena Terry, the famous bike builder, wrote:
“I really didn’t want to get off the bike. For those of you who wondered where I was for most of last month… well, I was riding my bike!”
Her experience is typical of how our customers feel when riding on Compass tires. Whether it’s in letters, e-mails or in person, hearing that our products bring so much joy is the best part of my job!
More information:

Continue Reading

Weekend Rides on Film: Gravel Racing and Rinko

rasputisa
Spring is coming to many places, and this weekend was filled with wonderful rides. Two of them were captured on video, and they inspire me as I plan upcoming outings on my bike. One is from the Rasputitsa Gravel Road Race in Vermont, the other from the Flèche Northwest. Both rides are challenges, but in very different ways. The Rasputitsa is all about speed, whereas the Flèche is about endurance. Both favor teamwork and put friendship above competition.
https://www.facebook.com/ansel.dickey/videos/vb.1441302451/10209667097421163/?type=2&theater
 
In the Rasputitsa Gravel Road RaceBicycle Quarterly reader Matt Surch was in a breakaway of four riders. In the video, you see them working smoothly on the gravel as they race to the finish. The top photo shows Ansel Dickey (left) as he made his winning attack. Matt Surch came second in this race, riding his Compass Bon Jon Pass 700C x 35 mm tires.
Matt’s teammate Iain Radford came seventh. Iain reported: “The Bon Jon’s allowed me to roll faster with less effort compared to everyone else in the chase group. I was able to let gaps go on the climbs to save effort and easily get back on the group using the descents.” (And unlike sponsored pros, these guys say this even though they paid for their Compass tires with their own money.)

Before departing for the Flèche, Hahn Rossman packed his bike for Rinko. The team started their ride in Olympia, but there weren’t enough bike spots for the entire team on the Talgo train. Hahn was glad that he could just carry on his bike after putting it into its Rinko bag. Theo took the time-lapse video. Even in real time, the entire process took less than 10 minutes.
sunrise
The team had a great ride, enjoying a challenging course over the gravel roads of the Willapa Hills. And the sunrise after riding through the night was gorgeous!
Enjoy the videos!
Further reading:

Photo credits:

Continue Reading

Gravel Racing on Compass Tires

matt_surch
When the Australian Matt Hayman won the European Paris-Roubaix race yesterday, it came as a huge surprise to everybody, including Hayman himself. However, nobody was surprised that Hayman rode on super-supple tires. With their tan sidewalls, Hayman’s tires looked like FMBs or Dugasts, but first reports insist that they actually were made by Continental. It’s an indication how far we’ve come if Continental really is making 28 mm tubulars with tan sidewalls and supple casings. (Of course, with pros, you always wonder what they really ride.)
Closer to home, there is little mystery in the tires that long-time Bicycle Quarterly reader Matt Surch (above) used to win Ontario’s season-opening gravel race, the Steaming Nostril. He isn’t sponsored by anybody, and we were excited to learn that he chose Compass Bon Jon Pass tires for his winning ride. I used the opportunity to catch up with Matt and ask him about gravel riding, bike and tire choices, and his training.
JH: Congratulations on winning the Steaming Nostril. Can you tell us a bit more about the race?
Matt Surch: Thanks Jan! It felt fantastic to kick off the season so well with my teammates! The Steaming Nostril is a 70 km loop from St. Jacobs, Ontario. The course begins with pavement, then mostly covers gravel roads that are well packed and have the typical potholes for this time of year. Long straight lines and strong winds favour those with strength and pack-riding skills.
After covering about 55 km, the course gets exciting! A new sector this year saw us enter a Mennonite farm on a dirt lane. We descended an absolutely gnarly rutted path into a valley, where we followed a freshly cut trail of grass and mud to a veritable muur [wall] of muddy singletrack. Completely unrideable, on any bike, this climb required cyclocross shouldering (below). After this sector, the race took us over a beautiful span of twisting and undulating packed dirt, some more pavement, and the final challenge: 6 or 7 flights of wooden stairs. From there it was about 50 meters to the finish line. The eclectic mix of surfaces and features made for a tactical and fun race.
matt_surch_steaming_nostril
You’ve been racing on gravel longer than most. What attracts you to that part of cycling?
I grew up through the 1990s obsessed with mountain biking, and that’s where I began racing. I raced cross-country for years, then transitioned to downhill, which I pursued through my early 20s. When I had enough of the grind of racing, I shifted focus to skills-based riding: dirt jumping, street (in the BMX sense), and park (skatepark) – squarely centered on fun and progressing skills. But then I was tempted to try a local ‘spring classic’ race, the Ottawa Bicycle Club’s Paris-Roubaix. Yes, that’s the real name.
Ian Austen started the event about 25 years ago, and it’s a cult classic in our region. It’s 75 km of mostly dirt roads with a number of forest sectors that are trails or double-tracks. The first year, I did it with a gang of friends, and we all rode fixed-gear bikes with 28 mm or larger tires. It was really fun, and a great way to get into ‘road racing,’ though it was obviously far from that. The next year I tried again, this time with gears, and was more of a participant in the race, though I had no idea what was going on up front. My third year, I was able to ride close enough to the front to finally understand what was happening, and that was the spark I needed to really latch onto road racing.
I love how the gravel races bring out a huge spectrum of riders, from those who take them seriously to those who consider them ‘challenge rides.’ We all ride the same courses, and we all struggle in our own ways. They also tend to be ‘open category’ races, so they let us friends race together, rather than being split us up into the usual race categories.
There’s generally a strong sense of camaraderie between riders, be they at the front, the middle, or the back. I love that, trying to smash each other in the race with attacks, then laughing about it and sharing food and drink afterwards. (My drink of choice is kombucha!) We all have war stories…
The community aspect of the gravel races really speaks to me, too. They tend to be run out of small towns that get behind the events, and that is really heartening. We get to travel to these places off the beaten track and learn about the history and culture of the regions. I love that.
There’s more to it. I’m rarely the strongest rider in a race, but I’ve got as much skill as just about anyone I face, so I always try to figure out how to leverage that. Often I race with team-mates, and we spend time in advance of the races trying to work out different strategies, scenarios, and contingencies. That’s really fun, and different from road racing, where you’ll often know that there’s a hard climb that will be decisive… Often it’s really simple on the road. For the gravel races, we think about at what point we want a break or split to happen, then try to execute that plan, knowing that at some point it will come down to pure power and skill to seal the deal. I find this really exciting.
The other aspect I find really fun is the equipment. Each race has different demands, and I love working out the puzzle every year according to the conditions we’ll face.
You mention the equipment. Tell us about your bike!
I tend to use my cyclocross bike for these races. I have a custom Steelwool cx bike built with Columbus Spirit for Lugs; it’s TIG welded. I don’t’ have anything against other frame materials, but this is a bike that fits me perfectly and has served me well for years. I’d like disc brakes and more tire clearance, but that would require a whole lot of new wheels! My frame has curved seat-stays for a bit of passive suspension, which I find works really well for me. On the cyclocross courses and gravel roads this frame is comfortable, which I believe makes me fast. It also ‘planes’ for me well, which I love. I go with a pretty typical ‘road position’ on my bike for all these races, just a bit less drop to the bars than my road race bike. The only change I make for cyclocross is moving my stem up 5 mm and rolling my bars up slightly.
nostril_bike
 
Wheels have always been a huge part of the picture for gravel racing, and I used to struggle with denting rims and puncturing. Over the last few years, I’ve been using Woven Precision Handbuilts carbon wheels, first for cyclocross (tubulars), then for everything I do on the road and cx bike. With the deep-dish rims, it took me a little time to adjust to the front end’s reaction to gusts of wind, but after a while I was fully adapted. I was amazed by how hard I could hit things with those wheels and not even have to true them. It turns out the deeper wheels can be very compliant, given their ability to bulge out their sidewalls (not the brake track) under impacts.
Believing that I am on equipment that gives me an edge gives me confidence. Most people would not tend toward deep wheels for gravel races, but I’ll take the aero gains whenever I can, even if going deeper adds a few grams.
nostril_tires
I’m a pretty massive tire nerd, and this applies to every discipline I ride. I started on 28s, but I’ve come to love larger tires for the rougher terrain. I’ve even used a Niner 29er mountain bike, set up with drop bars and 2” Schwalbe Furious Fred tires, for the roughest terrain, and it was great. But I’ve learned through trial and error that my preference is to use the least amount of tread possible and the least amount of volume possible for a given race, in order to strike the best balance of low rolling resistance and aerodynamics, so I use Compass Extralight tires whenever possible.
I can literally feel the aerodynamic difference between 32 mm Compass tires and 38 mm ones, so I think about the hardest section of a race and how narrow a tire I can use and survive with, usually. I choose the tire that will let me ride at 100% intensity and probably not puncture. Sure, I could use the 38 mm option, but they are overkill most of the time. Instead, I look at how rough the fastest descent will be, and what volume I’ll need to do that well and safely.
I choose tread (some sort of knobs, from a diamond file tread up) on my tires when there might be ice and snow (Continental Speed), a bit of off-road that will have some mud and/or aggressive turning (Clement LAS, Bontrager CX0), and a ‘full tread’ tire (Clement PDX) for off-road parts that are really gnarly and will be soft enough for full knobs to penetrate and grip into. However, it’s uncommon to need more than the LAS “diamond file” treads for anything I race.
nstoril_bikes_after
You won the Steaming Nostril on Compass Bon Jon Pass tires. You aren’t sponsored, so you could have chosen any tire. Many readers would expect you on knobbies for a muddy race. Why did you chose the Bon Jons?
I’d been testing the new tubeless 35 mm Bon Jons, and they were working extremely well in tubeless format on the pavement and dirt roads. Planning for the same course as last year, they seemed like a great choice, even if they were a bit bigger than I needed. If the Compass 32s were tubeless-compatible, I’d have considered them ideal. I wanted the low rolling resistance of the tubeless format and the puncture resistance!
As to the smooth tread, the gravel roads were totally wet and muddy, yet traction was not an issue at all. The only issue was keeping mud off my glasses and trying not to collect too much as it froze onto the bikes! We’d been told by a rival that there was a new crazy sector while we were lined up for the start, so we knew there would be a surprise. When I hit the rutted descent I knew that tire tread would be irrelevant; it would come down to having the front wheel swallowed or not. Mine was, and I went over the bars! Fortunately, mud is soft, so I was back on my feet within seconds.
The trail bits that followed were a bit more difficult on tires with minimal tread, but one can adjust by pushing a harder gear to reduce the torque that makes the rear wheel spin. In fact, I made up ground here on my rivals with their knobby tires, perhaps in part because the minimal tread of the Bon Jons was not picking up as much mud… Once out of that sector, I had the advantage back, as the rest was definitely suited to the smooth tires.
I always look at whether I can use Compass tires rather than my other options, which have more tread and are more robustly constructed. Essentially, I want the EL’s super-supple casing and low rolling resistance whenever I can use them. Because I’ve got the option of using up to the 38 mm-wide tires now, the tires can handle some pretty extreme rough stuff. With the wider tires, I can run low enough pressure that the tires can absorb sharp impacts rather than get cut. When I match the tire correctly to the conditions, I feel like I’m just floating along, totally in tune with the road. It’s the suppleness of the tires and the compound that contribute to attaining that harmony. I love that. Stiffer tires simply can’t feel that way, and there certainly are not any tires out there that compare in the 32, 35, and 38 mm 700c sizes.
I often think that I’m riding tires similar to the best tubulars the pros use for races like Paris-Roubaix, but without the hassles of tubulars, and with lower rolling resistance, especially with the tubeless Bon Jons. Honestly, I’m convinced the Bon Jons are the fastest rolling 35 mm tire the world has ever seen in tubeless format. I just can’t see how anything else could compare.
What tire pressure did you ride in the race?
Low pressures are key for traction and floatation on gravel. I used 50 psi (3.5 bar) on the rear and 47 psi (3.2 bar) on the front. I weigh about 162 lb (73.5 kg).
gravel_race
Sounds like there is an active gravel racing scene in Ontario. Tell us about it!
Around Toronto and Ottawa (my home town) there are a good number of gravel events that mostly focus on spring. Both cities have strong cyclocross and road scenes, which contribute to the popularity of these events. The season kicks off with the Hell of the North (formerly organized by Mike Barry of Mariposa) in March, followed by the Steaming Nostril (both in the Toronto area), Paris-Roubaix (we call it the Almonte Roubaix), the Clarence-Rockland Classic (outside Ottawa), and Paris to Ancaster (Toronto area), which is the biggest, pulling in thousands or riders, including cyclocross stars from the US. We head down to Vermont for the Rasputitsa Gravel Road Race in April, which is a favourite.
Later into the season we return to New England  for the fantastic Vermont Overland race, which is really hilly, and has some very challenging Class 4 ‘road’ sectors, which are referred to by locals as ‘Vermont Pavé’. This race is awesome, my favourite parcours of all, because it’s so technical and exciting. Plus, the event brings in such an amazing crowd, and their meal after is incredible.
How do you prepare for the races?
The spring races are the hard ones to prepare for, because we have full-on winter here in Ottawa. It’s dark, cold, snowy and icy from December through March, so we really have to be disciplined in order to get the fitness where it needs to be to be good for these races. While many locals head south during the winter for training camps, I stay home and put in lots of time on the trainer in the basement. I don’t really take a break after cyclocross season ends at the close of November, but just get onto the bike every day – normally in the morning before work, then at night – and keep moving. I go by feel rather than follow a rigid training schedule. That means I ride hard when I feel good, and I ride easy when I don’t.
There are a couple ‘anchors’ to my weeks over the winter.  On Thursday nights I started doing Zwift races this past winter, which ended up being amazingly high intensity training. I found I was able to push to 100%, whereas I couldn’t normally do that inside. These sorts of workouts are key for me through the winter, along with the shorter interval sessions I pepper in. I also like to work on things like high cadence, prolonged standing, and low cadence on the trainer. All of these things are meant to target weaknesses and give me more tools to work with in the races.
Every Sunday in the winter (except when the weather/roads are insane), 3 to 12 friends ride a three-hour loop on snow-covered dirt roads. We tend to draw a line at colder than -15° C at the start; if it’s colder than that, our feet have a hard time staying unfrozen. We do the loops at a pretty steady tempo, and the great thing is that the climbs are not so long that we get really hot, and the descents are not so long that we freeze. After a week of pedaling inside, these Sundays are special, even if we have to wear ski helmets, goggles, mitts and two pairs of shoe covers over winter shoes.
snow_surch
Obviously, you train a lot. As in most races, you probably won mostly because of your fitness. What other factors played a role?
Fitness was definitely a big factor, but my team-mates were also key to making the win possible. Marc Hunt was out in a break of 2 for 20 km, which forced our main rivals, Wheels of Bloor, to try to bridge. Iain Radford and I simply could chase down each attempt, and other riders helped. So that was pretty straightforward. Once they were absorbed, a split occurred, and it was a matter of reacting to attacks. I ended up going into that gnarly sector with just two others, one being last year’s winner.
What about rider skill? How is racing on gravel different from racing on pavement?
Because ‘gravel’ events can vary widely in terms of what they throw at riders, the range of skills required also varies for a rider who wants to do well across the board. The most road-like events we do, like the Clarence-Rockland Classic, only use actual roads – paved and gravel. There’s not a lot of turning, so riders don’t need to be really adept there. They do, however, need to know how to ride relaxed over rough surfaces, and choose their tires well. Wind is usually a factor in races like this, so if a rider is strong, but doesn’t have good pack riding skill, they won’t be able to do well. The longer races in the US, like the Dirty Kanza, are similar in that they are quite open and windy. If I was doing that race, I’d be all about my aerodynamics and making sure I was not riding alone until I had to.
The more technical courses, like the Almonte Roubaix, Paris-to-Ancaster, and Vermont Overland require specific off-road skills for riding light over roots, rocks, mud, and steep ascents and descents. The sectors these races use are essentially trails people would normally ride mountain bikes on. In our case, cyclocross bikes are the best choice for all the faster and smoother parts, so one has to be able to ride drop bars with skinny tires through all that rough stuff. So looking way ahead is essential, as is being light and fluid on the bike to ‘roll with’ changes of direction when the wheels deflect off rocks and roots. Or mud ruts!
Mountain biking teaches riders to stay calm, let go of the brakes, and just go with it when facing difficult sections, and this is exactly what is required on the ‘gravel bikes.’ Without suspension, it’s key to be able to hop over the worst obstacles that can smash wheels, and even slide both wheels through turns at times. Really, all the skills riders learn in cyclocross translate well, though there is often much more speed involved in these races, which is where mountain bike experience helps. But shouldering and running with the bike is a cyclocross skill that will sometimes be key in a ‘gravel race’. If you can get off and run, and be faster than riding, you should run!
One cool thing about some of the gravel races is that riders with very good descending speed can use it to catch back up after being dropped on climbs. You can’t win on the descents, but you can often ease up a bit on the last part of the climbs then catch back on without using extra energy. I love that.
What advice do you have for riders who want to try riding on gravel?
Riding on gravel must seem scary to a lot of riders, and I understand why. The fact that most ‘road bikes’ are sold with narrow tires (23 – 25 mm) can’t help the situation. Whenever I counsel friends and colleagues on new road bike purchases, I always encourage them to get a bike that fits at least 30 mm tires. A bike with 30 mm tires is so much more stable on gravel. But ‘gravel,’ as a category, is so ambiguous; the truth is that lots of dirt roads around here are actually really smooth in the summer, and don’t require anything special to ride. But if we’re talking about loose gravel, more volume in the tires is the name of the game. Over the years we’ve learned that volume is the key to stability on unpacked surfaces like those of gravel and dirt roads; knobs can’t do any work when the substrate under them is shifting.
Gearing might need to be lower than usual for getting out into the gravel, as these roads are often steeper than what we usually find paved. Compact cranks are always a great place to start!
A good pump is key to fixing the flats you’re likely to encounter while on gravel adventures! That’s ok, it’s part of the learning curve! It’s really important not to overinflate tires. Riding a low pressure avoids unnecessary cuts and improves comfort and stability. Don’t be afraid to get it wrong sometimes! Just stop to add air to your tires mid-ride, if they don’t feel stable enough, or they are bottoming out on the bigger bumps.
If you want to try an event, I’d suggest finding one close to home and jumping right in! While riders like me geek out on marginal gains stuff for all these races, the majority of riders don’t need to worry about any of that. Lots of events are doable on a ‘normal’ road bike with 28 mm tires or a mountain bike. If there are technical parts that will be hard to navigate, use mountain bike shoes and pedals so you can walk. It’s not a big deal to get off and take the safe way. If riders have rando bikes, awesome, those are great for these events! I’d suggest removing the fenders if grassy or freezing mud is involved, unless you have huge clearance. At the Steaming Nostril, fenders would not have worked at all. Ride with one or more friends and share the experience, or, make new ones! I’ve met so many fantastic people while doing D2R2 (Deerfiled Dirt Road Randonnee) over the years. Just give it a try!
Thank you very much, Matt, and good luck with the other races this season!
Further reading:

Photo credits (in the order they appear):
1. Zara Ansar, from Clarence-Rockland Classic 2015
2. Cycle Waterloo, Steaming Nostril 2016
3. Matt Surch
4. Rasputitsa Gravel Road Race 2015
5.  Matt Surch
6. Paris-to-Ancaster 2015 (photographer unknown)
7. Rasputitsa Gravel Road Race 2015
Correction: Initially, the front and rear tire pressures were reversed, showing a higher front tire pressure. Matt runs slightly more air in his rear tire than his front.

Continue Reading

Tire Pressure Take-Home

un-meeting_uphill

What is the ‘correct’ tire pressure for your bike? The simple answer is: Whatever feels right to you. Confused? Here is how it works:
In the past, many riders inflated their tires to the maximum pressure rating. Now most cyclists now recognize that the optimum pressure often is much lower.

But what is the right tire pressure? At Bicycle Quarterly, we’ve done a lot of research into the rolling resistance of tires at various pressures, and on various road surfaces.

Frank Berto’s tire pressure chart (above), first published in Bicycle Quarterly many years ago, has received much attention. (Note that the weights are per wheel, not for the entire bike.)

Berto made the chart in the 1990s, when tires were much narrower. Hardly anybody today still rides on 20 mm tires, and even 23 mm are on their way out! At the other end, 37 mm no longer is huge, as many of us ride 42 mm tires on pavement, and even wider ones on gravel. How does it all translate into the modern world?
tire_drop
Much of it depends on the tires you run. Berto measured the tire drop (above; how much the tire deflects for a given load and pressure) for dozens of tires. He then averaged the values, and drew his chart for a tire drop of 15%.

The 15% as desirable tire drop was based on the recommendations of several tire manufacturers, but not on actual testing. So the chart shows how much you need to inflate an average 1990s tire to achieve a tire drop of 15% – nothing less and nothing more.

A few years ago, Berto sent me all his original data. Looking over his measurements, it’s clear that supple tires – back then pretty much only the Michelin Hi-Lite – deflect much more than stiff ones, at the same pressure. This means that specific tires can vary quite a bit from the averages shown in the chart.

golden_gardens

To get the same tire drop with supple tires, you would need to run them at higher pressures. But is 15% tire drop really what you want with supple tires?

The answer is “No.” The 15% tire drop is an arbitrary value. However, even if it’s only by coincidence, the values in Berto’s chart actually work quite well for Rene Herse tires. They’ll result in more than 15% tire drop, but that is OK: Comfort and speed are optimized. And that is what really matters.

track_tire_test

The biggest surprise of all our testing (above) was this: For supple tires, pressure makes little difference in performance. We tested three Vittoria tires (Rubino, CX clincher, CX tubular; all 25 mm wide) and found that the supple CX models roll as fast at 70 psi as they do at 130 psi. (For the rest of the world, that is 5 bar and 9 bar.)

The reason is simple: Higher pressure decreases the energy required to flex the tire. Less energy is lost due to internal deformation (hysteresis). But higher pressure increases the losses due to the vibrations of bike and rider. More energy goes to suspension losses. The two effects cancel each other. Whether you pump up your supple tires super-hard or ride them squishy-soft, they have the same resistance.

On the other hand, truly stiff tires feel sluggish at 15% tire drop. The stiff tire is much harder to flex, so it’s useful to minimize that flex by increasing the pressure. For stiff tires, the suspension losses do not vary as much with pressure – they’re always high – since the stiff casing transmits a lot of vibration at any pressure.

Recently, Velo-News confirmed our results: The performance of a hand-made tire with cotton casing did not change at different tire pressures. And a stiffer tire rolled slower at lower pressures than at higher ones. (It’s nice to see that our results, after having been highly controversial for years, now are becoming generally accepted.)

It can be hard to believe this, because higher pressure feels faster. Here is why: When you go faster, your bike hits more road irregularities per second: The road buzz increases in frequency. Most cyclists know: higher speed = higher frequency.

Higher tire pressure cheats you into thinking that you are going faster, because it also increases the frequency of the vibrations: higher pressure = higher frequency.

It’s natural to assume that this means: higher pressure = higher frequency = higher speed, but that is incorrect. Instead, you are looking at two different mechanisms that both increase the frequency of the road buzz.

Even after years of riding supple, wide tires, this ‘placebo’ effect sometimes plays tricks on me. A supple tire absorbs vibrations better, so it can feel slower – until you look at your speedometer.

hahn_un-meeting

What does it all mean? Here is the take-home summary:

  • Stiff casings always will be slow. They are even slower at lower pressures.
  • Supple casings are fast, and pressure doesn’t matter.
  • On smooth roads, tire pressure is a matter of personal preference (at least with supple tires). High and low pressures offer the same performance.
  • On rough roads, lower pressures are faster. So if you want to optimize your speed on all roads, including rough ones, go with a relatively low, but safe, pressure.
  • Your tire pressure needs to be high enough to avoid pinch flats. If you get pinch flats, increase your tire pressure, or better, choose wider tires. Pinch flats are rare with wide tires.
  • On pavement, your pressure needs to be high enough that the tire does not collapse during hard cornering.
  • The minimum safe pressure is higher for more supple casings. Stiff casings hold up the bike more, and thus require less air pressure.
  • On gravel, you can run lower pressures than on pavement. On loose surfaces, the tires don’t collapse as easily, because the cornering forces are much lower.
  • Don’t run your tires so low that the casing cords start to break. That happens only at very low pressures, but if you start seeing multiple lines across the casing where cords have broken, inflate the tires a bit more.
  • Berto’s chart still is a good starting point. Inflate your tires to the pressures it recommends, then experiment by adding or letting out some air.
  • See what feels best to you. That is the optimum tire pressure for you. Don’t worry about tire pressure any further! At least on paved roads, you won’t go faster or slower if you change your tire pressure.

Even simpler, here is a summary in two sentences:

  • Ride the tire pressure that feels good to you.
  • When in doubt, let out some air.

It’s really that simple!

Further reading:

Continue Reading

Visiting Panaracer

panaracer_mt
As a child, I used to think of Japan as a densely populated place full of skyscrapers and freeways. Of course, those big cities exist, but much of Japan is very rural. So when I travel from Tokyo to visit the Panaracer factory, I get to experience that transition from city to countryside.
shinkansen
My trip starts with one of the incredible Shinkansen trains. These trains now travel at up to 320 km/h (200 mph). Their shapes are designed to reduce turbulence when two of these projectiles meet at full speed in a tunnel. (Imagine the pressure wave!)
fuji_shinkansen
On the way, the train speeds by Mount Fuji, and I am reminded why the Japanese revere this volcano so much. It really is stunning.
super_nozomi
In less than 2 hours, I am in Osaka, more than 500 km (310 miles) from Tokyo. But my trip is far from over. I now switch to the standard narrow-gauge Japanese railways, and board the “Kounotori Super Express” (above).
single_track
By American standards, it’s a fast train, and the trip through gorges and tunnels is spectacular. After 1.5 hours, I have crossed an entire mountain range, but my trip isn’t over yet.
green_orange_train
I now change to a local train, the kind that is used by schoolchildren and people going shopping in the next town. This train finally takes me to the small town where the Panaracer factory is located. From the station, it’s just as brief walk to the place where our Compass tires are made.
panaracer_mountains
What inspired our tires is also what the workers see when they look out of the factory gate: mountains.
panaracer_engineers
It’s always a privilege to meet Panaracer’s engineers (above). We present them with our ideas, they give us their feedback, and we discuss how we can further improve our tires. We discuss rubber compounds, casing materials, tread patterns, and other things that make our tires perform as well as they do.
yabitsu_tunnel
Several Panaracer engineers are avid riders themselves. All are as passionate about bicycle tires as we are, and I enjoy working with them immensely. And best of all, I get to enjoy the tires’ performance in the mountains that have inspired them.

Continue Reading

When Experts Are Missing Something

hahn_shiretoko
Recently, I posted about slick tires and why they tend to offer poor traction, especially in the wet. Almost predictably, some Internet “experts” declared that it was all wrong. One of the more polite comments was: “Wow, lots of misinformation in this article.”
I guess it’s normal: If your research is breaking new ground, the results aren’t what people think they know. But the unexpected isn’t always wrong.
What the “experts” really are saying is: “This isn’t what most people believe right now. It may take a few years until it becomes widely accepted.”
Illus.BQ.RollTest
The same thing happened when we first published Bicycle Quarterly’s real-road tire tests a little over eight years ago. Back then, the idea that higher tire pressures do not increase speed bordered on heresy.
The idea that tires roll faster the harder you pump them up seemed so evident that there wasn’t even a need to discuss this. Every tire company expert agreed with this. End of story. Or so it seemed.
MarkTiretesting
We were just as surprised by our results as everybody else. But after double- and triple-checking the results by running more tests, we concluded that the results were real.
Bicycle Quarterly has two people with Ph.D.’s on our editorial team, so we know how to design experiments, test hypotheses, and do statistical analyses to ensure that we are measuring real differences between tires and not just variations in the testing conditions. (The last point is very important, yet it’s often omitted in cycling research.)
How to explain these new findings? We realized that the “accepted wisdom” overlooked an important factor: Suspension losses caused by the vibrations of bike and rider consume significant energy. With higher tire pressure, suspension losses go up, and they cancel out any reduction in rolling resistance that comes from less internal deformation of the tire.
Previous testing had been done on smooth drums, were suspension losses don’t occur. That is why the experts missed a crucial part of the equation, and their conclusions did not match the real-road testing.
Roubaix94
Test results are fine and well, but the results must confirmed on the road. Apart from BQ staff and readers, professional racers were the first to adopt our idea of running wider tires at lower pressures. On the cobbles of Paris-Roubaix, you now find many pros running 30 mm-wide tubulars at 70 psi. The days when racers used suspension forks and narrow tires pumped to high pressures (above) are long past.
And even on the smooth roads of the Tour de France, the pros run 25 mm-wide tires, which is a huge step up from the 21.5 mm tires that were standard when I last raced on the road 15 years ago. In fact, I am envious that today’s racers have 35% more air volume in their tires than I did!
velonews
And finally, even the “experts” have come around. It was gratifying to read a decent explanation of suspension losses in Lennard Zinn’s recent Velo tire test:
“If you were riding on smooth glass, higher pressure would be better. On rough surfaces, however, a tire at lower pressure is better able to absorb bumps, rather than deflecting the entire bike and rider upward.[…] The less energy is sent upward with each bump, the less energy it takes to keep the bike rolling.” 
Even though most Internet experts now accept our tire pressure research, they aren’t any more open to new ideas than they were eight years ago. I read that tire tread is purely cosmetic, because tires don’t hydroplane. (True, but tire tread isn’t there to displace water.)  That slick tires stick better, because they put more rubber on the road. Various tire experts were quoted.
Could it be that the experts once again are overlooking something? Back in 2007, they didn’t realize that suspension losses were important.
Perhaps now the idea that the bicycle tire tread can interlock with road surface irregularities is still a little “out there” – even though it’s long been known and accepted by many tire experts. (I first read about it in a 1980s paper authored by a Michelin tire engineer.) Perhaps we have to wait another eight years until the idea is generally accepted…
GravelHelens
In the mean time, we’ll continue to do what we always do: ride our bikes. And we already know that the new Compass tires offer excellent traction, both on dry and wet roads. Everybody who has ridden them seems to agree. To me, that is all that matters. Because when it comes down to it, I’d rather be riding than discussing bikes online.

Continue Reading

Why slick tires don't stick well

Compass_Bicycles_700x35
 
During the R&D of the Compass tires, I was surprised how much difference tire treads can make. I rode three sets of tires with the same casing, same tread rubber and same width, but different tread patterns:

  • standard Grand Bois Hetres with large longitudinal ribs throughout the tire tread
  • “shaved” Hetres where all tread had been removed to make “slicks”
  • prototype Compass Babyshoe Pass tires with our optimized tread pattern

I crashed on the shaved Grand Bois Hetres when the roads got wet. I made the mistake of leaning over as far as I would have on the standard tires, and found that they offered much less traction in the wet.
During my first ride on the Compass Babyshoe Pass tires with their small angled ribs, I almost hit the inside curb. The extra grip of the new tread pattern made the tires corner on a much tighter radius, for the same rider input.
It became clear that slick tires provide relatively poor grip, especially on slippery road surfaces. And large ribs squirm and thus make the bike “run wide”. Why?
batmobile_bmw
How do slick tires work on racing cars and motorbikes? Slick tires for racing cars are so soft that they form a perfect imprint of the road. They interlock with the irregularities of the road surface. This means that they don’t rely only on the coefficient of friction for grip, but also form a mechanical lock on the road surface.
The downside of the soft tires is that they wear out in just a few hundred kilometers. Often, race cars need to change tires several times during a race. And once the road gets wet, slick tires go from phenomenal to almost zero grip. Water forms a very effective lubrication layer between tire and road (“hydroplaning”).
All this isn’t optimal, but car designers have no choice: Their tires use the same surface for cornering and acceleration. Any tread pattern fine enough to interlock with the road would be ripped off the first time the driver steps on the gas. The same applies to racing motorcycles, which put down a lot of power while still leaning over as they exit corners.
motogpdrift
In fact, the more powerful racing motorbikes can be “drifted” to safely approach (and exceed) the cornering limits. This would shred any fine tread patterns.
cropped-blogheader1
Bicycles are very different. They coast around tight corners. As a result, they use different parts of the tire for cornering and for accelerating. Here is how that translates into an optimized tire tread for road bikes:
Compass_tread_pattern
Center
When the bike is going in a straight line, the tread doesn’t matter much. Cyclists don’t have enough power to spin their wheels, and bike tires are too narrow to hydroplane. There is no need to evacuate water from the road/tire interface, and deep groves like those of a car tire serve no purpose.
The center portion of a tire can be slick, but we make ours with fine longitudinal ribs as a wear indicator. Once that tread is worn smooth, you have used up about 30-40% of the tire’s lifespan.
Dots or ribs that are angled or perpendicular to the tire’s rotation might increase the rolling resistance: They have to flex as the tire rotates. Perhaps it doesn’t matter much: The center portion of the tire will eventually wear smooth and become “slick”.
Compass_Bicycles_26x2.3
Shoulders
This is where it gets interesting. The tread on the shoulders provides traction when cornering, so it’s of great importance. You spend relatively little time leaning into a turn, so this part of the tire does not wear. The shoulder tread can be designed for optimum traction without compromise. How do we get the same “interlock” as the race car slick tires?
The best solution is to provide little ridges that “catch” on the road surface irregularities and thus interlock with the road surface. One advantage compared to the slick race car tires is that the ridges cut through the water when the road is wet, thus providing the interlock even in the rain. On wet roads, the coefficient of friction between road and tire is reduced by more than 50%, so the interlock between tire tread and road surface becomes much more important.
This idea of interlock between tire tread and road irregularities is nothing new. Michelin’s engineers pointed this out in a paper in the 1980s Bicycle Science Newsletter, and even then, it wasn’t presented as something new or revolutionary.
Since the pavement aggregate is random, you want to provide as many interlocking surfaces, oriented in as many directions, as possible. By making the tread as fine as possible, you have a good chance that a rib lines up with the edge of a piece of aggregate in the pavement. That is why small ribs work best. The ribs need to be strong enough that they don’t squirm during cornering (like knobby tires do). Otherwise, you’d reduce your cornering grip again, and also increase the tire’s rolling resistance. Fortunately, the ribs don’t have to be tall, which reduces how much they can flex.
That is how you arrive at a criss-crossing pattern of fine ribs to provide a maximum of interlocking surfaces. This type of tread pattern was standard on high-performance bicycle tires for so many years, and it appears that there was good reason for this. In the old days, rubber compounds were much less evolved and provided less friction especially in wet conditions. Without the interlocking ribs, the tires would have been very dangerous in the wet. Modern rubber compounds have improved the coefficient of friction, but interlocking still is important for grip, especially in the wet.
Edges
The outermost part of the tire tread never touches the ground. You only need it to protect the tire casing from cuts. This tread can be thin and doesn’t need any pattern.
That is the logic behind the Compass tire tread. It’s not complicated, but it seems to be the only way to optimize a bike’s tire tread. We aren’t the only ones to use this type of thread. It used to be common on most high-end performance tires, and today, a number of companies still use it.
Let’s look at the alternatives:

  • Slick and coarse tire treads give up many opportunities for interlocking, and thus will offer relatively poor grip, especially in the wet.
  • “Negative” treads, that just cut grooves into the tire, apparently are inspired by car tires, where they help prevent hydroplaning. But even very wide bicycle tires are too narrow for hydroplaning (and our speeds are too low, too). Perhaps a fatbike with slick tires at 50 mph could hydroplane…
  • Knobs will squirm in corners and thus make cornering unpredictable and dangerous. (Knobs are useful for traction in mud and snow, though.)

Shirabisu_Pass
Back to the title: Slick tires are based on a simplified, incomplete understanding of tire grip. They offer less traction in dry and, especially, wet conditions.
Better tire treads exist. It’s important, because the tread pattern makes a very significant difference in how well a tire grips and performs. Being able to lean into a corner with confidence makes cycling both safer and more fun.
Click here for more information about Compass tires.

Continue Reading

Why Wider Tires Corner Better

corner_adams
In our last post, readers noticed the image above and asked about cornering. How am I able to lean the bike so far?
Wider bicycle tires corner better than narrower ones. This may run counter to what many cyclists believe, but it’s easy to explain. The reason is the lower pressure at which you can run wider tires without risking pinch-flats. This has two effects:
1. Wider tires run at lower pressures and thus have a larger contact patch. This simply puts more rubber on the road and increases cornering grip. While simple physical theory suggests that friction should be independent of tire width – narrower tires are pushed onto the road with more pressure – in practice, wider tires provide more interlocking surfaces between road and tire, and thus provide more grip. If you don’t believe this – after all racing bikes use relatively narrow tires – look at racecars or racing motorcycles.
2. Wider tires absorb bumps better. This keeps the wheels on the road and provides more consistent adhesion. A narrow, high-pressure tire skips over the surface, which limits its grip. Even the smoothest asphalt is surprisingly rough. That is why race cars and racing motorbikes have suspension, and why they run their tires at 35-40 psi. If you inflate your tires to 90 psi or more, you are giving up a lot of cornering adhesion. (For the same reason, tires with stiff sidewalls don’t corner as well, because they don’t absorb the vibrations and bumps like tires with supple sidewalls.)
uphill_racer_rando
So much for the theory – how does it translate into the real world? A few years ago, we tested two titanium racing bikes against a 650B randonneur bike. We raced two bikes side-by-side up a steep hill (above), then turned around and rode back down the twisty descent.
I have talked about the uphill part of this test elsewhere, but the downhill part was equally surprising: In the corners, the racing bike with its 25 mm tires could not keep up with the randonneur bike on its 42 mm tires. The riders changed bikes, but it was always the randonneur bike that went down the hill faster. There were two corners, one extra-smooth with new pavement, the other bumpy. The wider tires were better in both corners. Not surprisingly, the advantage was magnified in the bumpy corner. And since the randonneur bike exited the corner faster, it also went faster on the straight that followed.
How did it feel riding the racing bike? I was one of the riders, and I consider myself a good descender, so I wasn’t happy when second tester Mark distanced me while he was on the randonneur bike. While I was riding the racing bike, I had to try hard to keep up. The first, smooth corner felt a bit unsettled, but then I really frightened myself in the second corner. I picked a good line that avoided the bumps, but my front wheel started skipping across the surface. I had to open the radius of my corner and went about a foot into the oncoming lane at the corner exit. In the same spot, the randonneur bike’s wide front tire simply keyed into the surface and rounded the corner without drama. (Both bikes were equipped with Compass tires, so the tread compound was the same.)
descent_blewitt
Of course, you can’t just slap wider tires onto any bike and expect it to corner like a machine custom-designed to optimize the handling. Here are some of the issues:

  • A wider tire’s larger contact patch stabilizes the bike. (This is called pneumatic trail.) If your bike’s geometry isn’t designed for wide tires, then your bike can feel sluggish in its response to steering inputs when you increase the tire size.
    Solution: Decrease the geometric trail to account for the pneumatic trail of the tires.
  • Wider tires tend to be a bit heavier, and thus have more rotational inertia. This makes the bike more reluctant to turn into a corner, or to change its line in mid-corner.
    Solution: Reduce the wheel size as the tire gets wider, to keep the rotational inertia within the range that gives the best handling.
  • Wide tires run at low pressures, but too low pressures can allow the tire sidewall to collapse under the cornering forces, which is not good at all.
    Solution: Make sure your tires are inflated enough to prevent sidewall collapse even under hard cornering. Especially supple tires don’t have much sidewall stiffness, and need a little more air pressure to hold them up.

Beyond that, technique can help. On bikes that are too stable because their tires are wider than is optimal, you may need to actively countersteer (that is, push the handlebars to the outside of the curve) to get the bike to lean. On optimized bikes, you do that, too, but you never notice it because the amount of countersteer is totally intuitive.
Overall, there is little doubt that wider tires corner better, all things being equal.
Further reading:

Continue Reading

Paris-Brest-Paris: Compass Tires and a New Book

before_pbp
This year’s PBP saw a significant number of riders on Compass tires. Of course, we (Jan, Theo, Hahn) rode them, too, but it’s always nice to hear from others how our products are doing.
J. O. from Vancouver, B.C., and his wife rode a tandem. We gave them our samples of the Rat Trap Pass 26″ x 2.3″ tires, which were hand-delivered to the bike check the day before the start (above). Putting on new tires just before the big ride takes confidence, but these riders were not disappointed:
“The Compass Rat Trap Pass tires were an immediate upgrade in terms of comfort. Cobbles and chip seal went from being a jarring distraction and energy sink to a slightly noticeable background hum. My wife noticed and appreciated the extra comfort the Rat Trap Pass tires provided, and she doesn’t want to go back to other tires, either.”
melinda
It’s always fun to see old friends at PBP. I’ve known Melinda Lyon from Boston (above) for many years, and for this year’s PBP, she was on the new Elk Pass 26″ x 1.25″ tires. Her report:
“I loved the tires. They really feel smooth even on the chipseal roads of France. No flats, no problems. Incidentally I seemed to have less shoulder, back problems and less of a sore butt than previous years but there were some other variables to that. On downhills, I felt like I was flying and catching heavier riders just with the tires rolling so well.”
There were others who provided unsolicited feedback:
I’ve been riding Barlow Pass tires all summer. No flats! Put on a new set for PBP. No flats, no hand numbness, no saddle sores. I credit the tires more than anything. Thanks for making my bike ride so nice!

— J.K., Belgrade, MT

“I bought the Stampede Pass Extralight tires for P-B-P… Usually my hands hurt on brevets, and I have to shift hand position often. With these tires no pain at all, and only a little tingling in the little and ring fingers afterwards. It is probably the most noticeable performance-improving change I have ever made to my bicycles.”

— G.P.K., Slagelse, Denmark
BookSyPBPFr2015_cover_1000

Whether you were able to participate in this year’s PBP or not, you may want to learn more about this fascinating event. Jacques Seray has updated his book on PBP with information about the latest edition, including Björn Lenhard’s incredible 600+ km breakaway.
BookSyPBPFr2015_03
The text is in French, but the photos alone make this book a must-have. Seray has assembled a vast treasure trove from the 124-year history of PBP, going back to the very first “utilitarian race” of 1891. Hundreds of photos allow you tollow the early racers on their incredible rides, join the mid-century randonneurs as they battled with wind and rain unsupported, and relive recent editions of this great event. The new book just has been released, and we have it in stock now.
For more information about Compass tires, click here.
For more information about the PBP book, click here.

Continue Reading

New Compass Tires in Stock

rat_trap_black
The four new Compass tires are in stock now! They are the Rat Trap Pass (26″ x 54 mm), Switchback Hill (650B x 48 mm), Bon Jon Pass (700C x 35 mm), and Elk Pass (26″ x 1.25″).
The Rat Trap Pass (above) is the ultimate expression of our new Enduro Allroad tires. With its 54 mm width, it is incredibly plush on rough gravel, yet thanks to the smaller 26″ wheel size, it has the same rotational inertia as a medium-width 700C tire, and thus handles like a good road tire on pavement.
The Rat Trap Pass has already proven itself in this year’s Paris-Brest-Paris, where it provided wonderful comfort and security for a tandem team on the rough roads of Brittany.
switchback_hill
At 48 mm wide, the Switchback Hill is our largest 650B (27.5″) tire yet. Named after the first major climb in the Oregon Outback gravel race, the extra floatation gives you more speed and security when the going gets really rough. 30% of the Oregon Outback is on pavement, so we designed this tire to roll as fast and grip as well as a good racing tire. With this tire, you truly have the best of both worlds. The Switchback Hill also can transform the performance of your 27.5″ mountain bike on gravel or paved roads.
The prototypes of the Switchback Hill tires have been in demand among BQ contributors. Fred Blasdel took Alex Wetmore’s Switchback Hills on an epic ride across the Cascades, and apparently he has no intention of returning them, since he likes them so much! (It’s OK, we’ll just have to give Alex a new set.)
bon_jon
The Bon Jon Pass is our Goldilocks tire: at 700C x 35 mm, it fits bikes that have extra clearance around the Stampede Pass (32 mm), but not enough space for a Barlow Pass (38mm). Whether smooth gravel or rough pavement, the Bon Jon Pass will make your bike fly!
elk_pass
The Elk Pass 26″ x 1.25″ tires (32 mm-wide) are superlight tires for bikes with 26″ wheels. If you are looking for the fastest, lightest 26″ tire ever made, this likely is it. Not only does it weigh just 178 g, but it uses the Compass Extralight casing and our ultra-sticky tread rubber for the ultimate in suppleness and cornering grip. It also is a great emergency spare tire for those traveling off the beaten path with 26″ wheels. The Elk Pass already has proven itself on challenging rides in the Cascade Mountains and in this year’s Paris-Brest-Paris.
Like most Compass tires, the new tires are available with “Standard” casings and tan sidewalls, as well as with “Extralight” casings in a choice of black or tan sidewalls. (The Elk Pass 26″ x 1.25″ is available only with Extralight casing and tan sidewalls.)
Click here for more information about the “Standard” and “Extralight” casings.
Click here for more information on the new tires or to order.

Continue Reading

Compass Tires and Tubeless

 
no_tubes
I was trying to put a photo of the new Compass tires’ bead here, but it’s hard to photograph the difference… What is important is this: our upcoming Compass 26″ x 2.3″, 650B x 48 mm and 700C x 35 mm tires will be tubeless compatible!
You’ll just need to use a tubeless-compatible rim, the right rim tape, and put sealant into the tire. The new Compass tires feature a new bead shape that can be used with either inner tubes or set up tubeless.
The new bead shape is designed to provide a better interlock with the rim. This reduces the risk of the tire coming off the rim. Even so, tubeless setups put bigger stresses on the tire, and when set up tubeless, tire pressure is limited to 60 psi (4.1 bar). For the wide tires, this is no problem, as you don’t need to run them at high pressures.
Of course, many of our customers already have set up the existing Compass tires tubeless. However, we cannot recommend this, since the bead shape isn’t optimized for tubeless installation. If you try it, use your discretion…
travel_gifford
With the new tires, these concerns no longer will exist. It’s an exciting development, but we are also glad that for the majority of us, who continue to use tubes, the new bead works just like the old one.

Continue Reading

Testing the Compass Elk Pass Tires

mt_adams
We recently received the first production samples of the new Compass tires. We’ve been testing the high-volume tires on our own bikes, but we don’t have any bikes designed for the 26″ x 1.25″ Elk Pass tires.
Fortunately, a Japanese friend was visiting, and she took the new Elk Pass Extralight tires on a tour of the Cascades, roughly following the first part of the Volcano High Pass Super Randonnée.
no_maintenance
How would the 32 mm-wide superlight tires fare on a ride that encompasses some of the most challenging roads, whether gravel or paved, that the Cascades have to offer?
rough_road
The roads were indeed rough, but the tires fared fine. In four days of riding, she had one pinch-flat, and no other problems. She noticed (and liked) the improved comfort, both on gravel and on pavement, compared to the Panaracer Paselas she usually rides.
dusty
I was glad to hear that, because these are some of my favorite roads, and the landscape is spectacular. But if you are continuously “underbiking” or suffering from multiple flats, it’ll take the fun out of the most scenic ride.
muddy_fork2
The new tires, despite their ultra-light weight and minimalist construction, not only handled the challenging ride just fine, but also, thanks to their suppleness, made it more enjoyable.
aero_tuck
She reported that the tires were sure-footed on pavement – which is their main intended use. Under heavier riders, the 32 mm width is a bit marginal for really rough gravel, but if you are looking for the fastest, lightest 26″ tire ever made, this probably is it. Not only does it weigh just 178 g, but it uses the Compass Extralight casing and our ultra-sticky tread rubber for the ultimate in suppleness and cornering grip.
elk_pass
Now she has Rinko’d her bike and headed back to Tokyo. We look forward to hearing how the Elk Pass tires fare on the roads of the Japanese Alps where she usually rides.
Meanwhile, the main shipment of our new tires will soon head the other way across the Pacific, and we should have all models in stock by the end of the month (August 2015). We’ll announce them here and in our customer newsletter when they arrive.

Continue Reading

Inner Tube Quality

SchwalbeTubes
Inner tubes often seem like generic commodities. One is as good as the next – so buy the cheapest one… I used to think that, too, until I started to see split seams, valves separating from the tube, and other mysterious flats that were not caused by “outside influences”. Around kilometer 1000 during the 2007 Paris-Brest-Paris, the seam split on a brand-new Michelin tube that I had bought at a control. (I had good luck with French-made Michelin tubes, but this was one of their Asian-made budget tubes.) It was a distraction I did not need at that point in the ride.
On the other hand, the Schwalbe 650B tubes I had been using always had been flawless. It became obvious that they were made to higher quality standards. So we decided to add Schwalbe tubes to our program. Initially, we intended these as “add-ons” for customers who were ordering tires anyhow. We were surprised how many customers ordered tubes just by themselves. Several customers thanked us for making these tubes available, and commented how they were tired of problems with the generic tubes they bought at their local bike shop…
pinch_flat
Nobody likes flats, and fortunately, as we have switched to wider tires, we get far fewer flats. Now we can enjoy the comfort and speed of supple tires without added puncture protection, yet not worry much about flats. But there is no protection against faulty tubes… (The photo above shows a pinch flat. On some very rough gravel, even 42 mm tires are not wide enough…)
I also like to run slightly undersize tubes in my tires. Not only does it save weight, but it also makes the tube easier to install. (Trying to get a slightly stretched-out tube into the tire without creases and folds can be a challenge.) With quality tubes, you can run slightly undersized tubes (say a 28 mm tube in a 32 mm tire) – at your own risk, I hasten to add! The walls of quality tubes are uniform in thickness and will stretch evenly. Budget tubes often have thin spots, which don’t respond well to stretching.
(Superlight tubes always should be sized correctly for your tire, since they are too thin to stretch much. However, some tubes aren’t labeled for all the sizes they fit. For example, the Schwalbe SV14A tubes we sell are labeled for 26″ tires, but they also fit 650B x 38 – 48 mm.)
Better tubes don’t make your bike ride better… so if you are on a tight budget, get the best tires you can afford, and use cheap generic tubes. Be prepared to fix an extra flat once in a while, but at least you get the performance, comfort and pure fun factor of great tires. However, if want quality in all your components (or if you are entering a big event and want to decrease your risk of flats), using quality tubes means that you have one less thing to worry about.
Click here to learn more about the tubes (and tires) Compass carries.

Continue Reading

Compass Tire Prototypes: Really Big Tires!

travel_gifford
Our very first Enduro Allroad prototype tires started out as knobbies with supple casings – then we had the knobs shaved off by Peter Weigle. We wanted to test the concept of a very wide, supple tire before committing to expensive tire molds. We were happy to report that the tires performed even better than expected! So we decided to proceed.
Last week, the project reached another milestone: We received prototypes made from the actual production molds. So while these are made as a very small batch and required even more hand-work than the final tires, they are basically the tires that you will be able to buy and ride in a few months.
compass54-559
The first samples we received were the 26″ x 54 mm tire. (For some reason the tire mold was changed to 58 mm after we approved the text!) This batch uses the “standard” (supple) casing. When we put one of the tires on the scale, it weighed 454 grams – quite light for a tire this wide.
26_caliper
Mounted on a 23 mm-wide rim, the tire measured a little over 49 mm. In the two days since, the tire has “grown” by 2 mm. The “Extralight” tires tend to stretch even more, so when used with wider rims, they’ll probably be close to the anticipated 54 mm.
compass48-584
Then we received a second box… This time, it contained the 650B x 48 mm tires – made with the extra-supple “Extralight” casing. Out came the scale again, and we measured 413 grams – remarkable for such a big, puffy tire.
650B-caliper
Mounted on a 23 mm-wide rim, this tire measured just over 48 mm right away, and like the 26″ tire, it has grown 2 mm in the days since we mounted it. That means that this tire is slightly wider than planned. Its width is just a millimeter or two narrower than the 26″ tire.
650B_gifford
Of course, measurements don’t tell us much about the tires: What we really want to know is how they ride. Fortunately, our friend Alex Wetmore has two bikes with similar front-end geometries (both have 40 mm trail). One is his “normal” bike, set up for 650B tires (above). The other is his “Travel Gifford”, which runs 26″ tires (photo at the top of the post). These two bikes are perfect candidates to compare the new tires.
Aired up to about 28 psi, I took to the streets and trails in Seattle’s Ravenna neighborhood. On the broken pavement of the residential streets, I wondered why we don’t ride these tires all the time. Even the 42 mm Babyshoe Pass tires of my Urban Bike, which I had ridden to Alex’ house, were surpassed for comfort and secure handling by these even bigger tires.
Riding the two bikes back-to-back, the differences due to the different wheel sizes were very noticeable. The 26″ bike felt very nimble and agile. It was easy to pick a line, but the handlebars required a light touch to maintain that line. The 650B bike, with its larger wheels and greater rotational inertia, felt much more stable. It required more input to change its line, and catching a slide on gravel took a hair longer than it had on the 26″ bike. The 650B bike also had an (empty) front rack, which further stabilizes the steering. While the steering of the unloaded 26″ bike was a tad light, adding a rack and handlebar bag would make it more stable. Both bikes handled fine, they were just at the opposite ends of what I consider “fine handling”.
The real revelation came on gravel. Both bikes felt like good road bikes. The uphill traction was amazing. Sprinting out of the saddle was easy. Only the cornering speeds were lower than on pavement – when the gravel starts sliding under your wheels, no tire can maintain traction. These tires really are a revelation – they have changed how I think a bike can perform on gravel.
Production of the new tires is scheduled, and we hope to have them in stock by July or August. Click here for more information about Compass’ existing tire program.

Continue Reading

Reviews of Compass Tires

gravelbike_2
When you design a product, develop it, test it and finally bring it to market, you wonder how it will be received. Of course, you are confident that others will like it as much as you do – you wouldn’t have released it if it didn’t meet your high expectations. Still, it nice to hear from customers that they enjoy the product. Perhaps even more gratifying are independent reviews. These people have nothing invested in the product, and they usually have significant experience with similar components.
Recently, there have been two reviews of our Compass tires.
rbr
“These Tires Expand Your Riding Universe” declared Fred Matheny at Roadbikerider.com after riding the 700C x 38 mm Barlow Pass Extralight tires. From somebody as experienced as him – he has been testing bikes for decades – it was particularly satisfying to read:
“The puffy tires rolled at my usual speed on pavement and handled the unpaved surfaces with plenty of traction in loose corners and surprising comfort even on washboard.”
You can read the full review here.
gravelbike
Mark Chandler at the Gravelbike blog tested both the Stampede Pass and Barlow Pass tires. He wrote:
“As good as the standard Stampede Pass versions are, the extralights are in a completely different league. Plush doesn’t even begin to describe how the extralights ride. The extralight Compass tires practically floated over chipseal roads and broken pavement.”
The full review is here.
Developing new tires takes a large amount of time, effort and money. It’s satisfying that riders and reviewers enjoy them as much as we do. Because that is why we made them in the first place: So we and others could enjoy riding our bikes even more!
 

Continue Reading

The Enduro Allroad Bike

enduro_allroad_cobbles
Last year’s Oregon Outback was a great test for the ultimate gravel bike. The course consisted of 1/3 rough and soft gravel, 1/3 smooth gravel and 1/3 pavement. The situation is similar to our favorite local rides: We leave from our backdoor on pavement and ride up to the mountains, where we explore gravel passes far off the beaten path.
What is the ideal bike for this type of riding? We approached the subject by evaluating the real-world performance of different bikes, without regard to tradition and established practice. As we reported in more detail in the Spring 2015 Bicycle Quarterly, we found:

  • Road bikes are faster than other categories (mountain bikes, fat bikes, etc.).
  • The widest tires that can fit between the chainstays of a road bike measure about 52-54 mm. Any wider, and you have to use mountain bike cranks with wider tread/Q factor.
  • Using 26″ rims keeps the outer diameter of the wheel similar to a 42 mm-wide 650B wheel. This makes it possible to use short chainstays, and it also maintains the nimble handling we enjoy in our bikes.
  • Our testing has shown that the small differences in wheel size between 26″, 650B and 29″/700C don’t affect how well a tire rolls over moderately bumpy terrain.

With one question remaining:

  • We’ve already seen that supple casings are faster and more comfortable, but what happens if we make a supple tire that is 50+ mm wide? Nobody had ridden supple tires that wide on the road, simply because no such tires have been available.

enduro_allroad_prototype
There was only one way to find out: Make some prototype tires! Thanks to our cooperative effort with Panaracer (who made a few sets of knobbies with the Compass Extralight casing) and Peter Weigle (who then shaved off the knobs), we were able to get prototype tires with the extra-supple casings, but in a 26″ x 2.3″ size (above). Then we went out to test them, using Alex Wetmore’s “Travel Gifford”, a road bike that is designed for wide 26″ tires (below).
gifford_rattrap
What did we find out? Off-pavement, the wider tires are absolutely amazing. Perhaps that is not surprising, since the tires hold 70% more air than a 650B x 42 mm tire! On these 51 mm-wide prototype tires, the bike simply floats over rough gravel, yet the sensations are those of riding a road bike on pavement. With the low tire pressure and supple casing, traction is amazing. Sprinting up hills out of the saddle is easy, where bikes with narrower tires simply spin their rear wheel. Now I understand why many professional mountain bike racers ride on FMB or Dugast tubulars.
enduro_allroad_web1
The biggest question for us was how the new tires would perform on the road. After all, tires are big air springs, and the more supple the casing, the less damping you get. Would the bike bounce down the road like a basketball?
We are glad to report that this isn’t the case. If the tire pressure is too high, the bike gets a little unsettled on undulating pavement. The window between “too high” and “too low” pressure is smaller than on narrower tires. In that sweet spot, the bike rides and corners like a road bike, except with much, much more grip on dry roads. The contact patch is huge, and more rubber on the road results in more traction. The lower tire pressure means the wheel doesn’t skip over surface irregularities, so it never loses traction. It’s amazing how far you can lean over on these tires without even getting close to the limits of tire adhesion. (That is why racecars have extremely wide tires.)
What about rolling resistance? We have not done any carefully controlled tests yet, but our on-the-road experience indicates that it’s no higher than narrower tires. Whoever rode the Enduro Allroad Bike during our testing easily kept up with the rest of the group.
So what are the drawbacks? Well, there are a few:

  • You can use these tires on most mountain bike frames, but if you want to use “road” cranks with narrow tread (Q factor), your frame needs to be carefully designed and built to fit the ultra-wide tires.
  • Fenders will not be able to wrap around the tire as they do on bikes with narrower tires, since you cannot make the fenders much wider than 60 mm while keeping a “road” chainline. (The chain would hit the fender in the smaller gears.) The solution probably is to use a 60 mm-wide fender with a shallow profile and mount it a little higher above the tire.
  • As noted earlier, the tire pressure needs to be maintained more carefully.
  • Since the tires are so soft, the bike tends to get deflected by longitudinal depressions in the pavement a little more than bikes with narrower tires.
  • It appears that the bike is more likely to shimmy with tires that wide.

For bikes that see mostly pavement use, with only occasional forays onto gravel, 650B x 42 mm tires will remain my preferred option. But I know I’ll add an Enduro Allroad Bike to my stable for those rides where we spend significant time on gravel.
enduro_allroad_rocks
What about the name “Enduro Allroad Bike”? We wanted to emphasize that it’s a road bike, not a mountain bike. Yet it’s not limited by its narrow tires like a typical road bike. We already use “Allroad” for our 650B bikes. To emphasize the “go-anywhere” capabilities, we added “Enduro”. A road bike that can go on any road and beyond…
For those of us who would prefer to float over gravel rather than “grind” through it, the Enduro Allroad Bike is an exciting new development. Compass Bicycles will offer the Rat Trap Pass, a 26″ x 2.3″ (54 mm) tire specifically designed for this type of bike. Rawland is working on their Ravn, the first production Enduro Allroad Bike that is designed around this tire. MAP also is considering making a small production run of Enduro Allroad Bikes. Of course, custom builders can make them, too. And other companies will probably offer them as well, since they make so much sense and are so much fun to ride.
If you want to try supple, ultra-wide tires but still prefer to stick with 650B wheels that you may already have, Compass will offer the Switchback Hill, a 650B x 48 mm tire. There are many 650B bikes that can fit a tire that wide, and you’ll get 30% more air volume than a 42 mm tire offers. Both new tires will be available this summer.

Continue Reading

Rene Herse Tires: Standard vs. Extralight

state_championships
Rene Herse tires are available in two versions: standard and extralight. What is the difference between the two?
The difference is in the casing. The standard casing is already quite light and supple, but for the Extralight, we worked with our Japanese supplier to push the envelope further. These tires use a casing material that is also used on high-end tubular tires, and not usually available for clinchers. Here are the differences between the tires:

  • Comfort: The standard casing offers exceptional comfort, but the extra-supple Extralight is yet another step closer to ‘tire nirvana.’
  • Speed: While we haven’t tested these tires under controlled conditions, the Extralight is even faster than the already-fast standard version.
  • Puncture resistance: Both versions use the same tread rubber and thickness, so the puncture resistance is comparable.
  • Sidewall cut resistance: If the Extralight casing has one drawback, it’s that the sidewalls may be easier to cut on sharp rocks. Even so, I rode the Oregon Outback 360-mile gravel ride on Extralights without a flat or any damage to the sidewalls.
  • Weight: The Extralight casing is significantly lighter. Depending on the tire model, the weight difference is 25-35 g (10-15%).
  • Cost: The Extralight costs more.
  • Color: Both models are available with tan sidewalls. Only the Extralight is available with black sidewalls.

So the Extralight is more comfortable, faster, lighter and available in more colors. The standard model is less expensive and less likely to suffer from sidewall cuts. Both offer the same puncture resistance.
I ride the Extralight on all my bikes, because I love their feel and comfort. If you are on a budget or ride on rocky trails a lot, the standard version may be a better choice.
Click here for more information about Rene Herse tires.
What about the photo? Hahn took it at the 2014 Washington State Championships, where a rider on Compass/Rene Herse 28 mm tires took 3rd place in the (very competitive) 50+ age category. The good placing was due to his legs, but it’s nice to know that his tires didn’t hold him back.

Continue Reading

Research & Development

Shirabisu_Pass
Over the last decade-and-a-half, I’ve thought a lot about product development. Long before Bicycle Quarterly and Compass Bicycles, I was involved with several companies as a technical writer and translator. Part of my job was writing instructions, so I got to see product development up close.
From my experience, product development ideally has three components:

  1. Skilled users who are sensitive enough to report what they experience.
  2. Scientists who design tests to confirm those observations and isolate the factors involved.
  3. Engineers who translate those findings into better products.

With Bicycle Quarterly, it didn’t take long until we got involved in No. 1. We rode many bikes over challenging courses, and we noticed differences in how they performed, how they handled, and how they felt.
From those observations, it was a small step to No. 2. After all, our editorial team is made up of scientists, so the question “Why do some bikes ride/perform/handle better than others?” came up quickly. We began testing tires, we tested our hypotheses about frame stiffness, and we rode different front-end geometries.
No. 3 was a logical next step – what good are scientific findings if they don’t lead to bicycles people can ride? So we started Compass Bicycles to translate the results of our research into better bicycle components.
reifen_1005-2
Sometimes, steps 1 and 2 are reversed. That is how our tires came about. I hadn’t thought much about tires, until I saw a tire test in the German magazine TOUR. (By the way, the title in the photo above translates to “Roll Well”.)
Among other things, TOUR tested the tires’ rolling resistance. They found significant differences, but downplayed them by saying that the difference would “only” amount to 138 seconds in a 40 km time trial. That got me thinking: First of all, more than 2 minutes in a time trial is a huge difference. When I raced, 10 seconds over 10 km made the difference between first and fifth place. Could the faster tires have made me a consistent winner? More importantly, speeds are lower for the long rides we now enjoy, so rolling resistance is even more important.
Talking with Mark Vande Kamp (friend, riding companion and fellow Ph.D. on Bicycle Quarterly‘s editorial board), we decided to see whether we could replicate TOUR‘s results, but at lower speeds. We bought a set each of the fastest tire in the TOUR test, as well as a slower one. We scouted a location for a rolldown test, and one Saturday morning, we installed the test tires on our bikes and headed to the hill. I rolled downhill, first on one tire, then on the other (always using the same bike, of course). Mark timed me and found that the differences were quite large: about 10% faster with one tire than the other. We repeated the experiment, and the results were the same. Wow! Tires did make a larger difference than we thought. We knew we had to test this further.
We then went on a long ride and discussed what we wanted to test. Different tire models, obviously, but also different pressures. After all, we always were torn between inflating our tires to the maximum pressure to obtain the highest speed, and reducing the pressure a little to improve comfort. How much speed did we lose if we went for comfort? We also decided to test the same tires in different widths. And worn tires against new ones, to determine how much of a difference tread thickness makes. (Worn tires have a thinner tread, but otherwise are the same as new ones.)
Test_Woodland
The testing took a lot of time and effort, but the results were worth everything we put into it. We found out that the tires I had been using were among the slowest tires in our test. Simply replacing my tires allowed me to stay with previously faster riders during brevets. And when I rode alone, I consistently set personal bests, despite my training being the same as before.
As a positive side effect, the faster tires also were more comfortable. However, comfort was relative: The fastest tires in our test were only 24 mm wide – too narrow for true comfort on backroads.
Our research showed ways to improve these tires. We found that tire pressure did not have a significant effect on speed. This opened up a whole new way forward for tire design. Instead of trying to make wider tires withstand high pressures (which requires strong, stiff casings), wider tires should be made supple casings. Despite running at lower pressures, they’d be much faster.
GrandboisCypres
At the time of our tire tests, we just had started to sell the first-generation Grand Bois tires (above). We were disappointed that they did not score well in our tests. We shared our results with Grand Bois and Panaracer, and they came up with an improved version that had a more supple casing. That was the first product that came directly out of Bicycle Quarterly‘s testing.
Over the next few years, the Grand Bois tire program expanded, and we were able to test our findings on the road. We found that even with 42 mm-wide tires, our bikes were no slower than bikes with narrower tires.
tires_comp_700_28
We felt that further improvements were possible by optimizing the tire tread for performance. The tread on the shoulders of the tire only contacts the road during hard cornering, so it doesn’t wear out. We could make this thinner, so the tires would be even more supple and faster. We tested many tread patterns to obtain an optimum of cornering traction both on dry and wet roads. The result were our Compass tires. Our customers rave about their comfort, speed, cornering grip…
Our tires are just one example of the symbiotic relationship between Bicycle Quarterly and Compass Bicycles. Without Bicycle Quarterly‘s research, we wouldn’t have known that the tires we were using were slow. And without Compass Bicycles, our research would have remained of little use to riders. We would have outlined “ideal” performance tires, but without anybody making them, that knowledge would not have improved our riding experience.
cascade_ride
The main reason Compass components exist is so we can use them on our own bikes! And I truly believe that our riding experience has improved in many ways since we starting riding on wide, supple tires.
Click here to learn more about Compass tires.

Continue Reading

Tire Pressure: Data and Details

Illus.BQ.RollTest
A little while ago, I wrote about how new scientific research has allowed us to design wide, supple tires that offer the speed of narrow, high-end racing tires. The key finding is that above a certain threshold, increasing tire pressure no longer results in lower rolling resistance. While these new data have become widely accepted – witness professional racers adopting wider tires and lower pressures – it’s natural that new ideas are met with skepticism. In order to contribute to a better understanding of how tires work, I’d like to share more data from Bicycle Quarterly‘s testing.
tire_pressure_rolldown
The data above came from Bicycle Quarterly rolldown tests of various tires. The results indicate that above a certain threshold, for clinchers, tire performance increases only very slightly, if at all. It’s not surprising that the 38 mm-wide Mitsuboshi tire rolled faster at 35 psi than at 25 psi – it was hardly rideable at the lower pressure. But increasing pressure to 55 psi resulted in no speed increase.
We saw the same for the 27 mm-wide Rolly-Poly. Somewhere between 55 and 85 psi, higher pressure no longer resulted in significantly increased performance. Going from 85 to 105 psi resulted in only a minimal increase in speed. For the two tubular tires, the effect was reversed: Higher pressures actually reduced performance.
tire_pressure_rolldown_2
We’ve confirmed this finding numerous times. Above is another set of test runs (pressures are in bar/psi). For these 32 mm tires, increasing the pressure from 7o psi to 85 psi brought no significant change in performance. (The apparently slower speed at 85 psi is not statistically significant.) Please note that the values you see here are not corrected for temperature, so you can’t compare different tires. (The pressure runs were done consecutively, so temperature didn’t change from one pressure to the next.)
tire_pressure
We discussed the measurements with power meters in the previous post (above). That data also has been confirmed multiple times, at different speeds.
cypres_pressure
Above is data from running ultra-high pressures, up to 200 psi. Performance did not change with increasing pressures. (Don’t do this at home, 14 bar/200 psi is not safe with these tires!) I could bore you with even more data, but I think this is pretty convincing, especially since we’ve confirmed numerous times that our tests are repeatable (testing the same setup multiple times yields the same results) and statistically significant (meaning we aren’t just looking at random noise in the data). That is important, because all too many studies are based on single test runs, which don’t meet basic scientific requirements. Now that we’ve conclusively debunked the old view of “higher pressure = more speed”, let’s look at some of the details in the data above.
Rough vs. Smooth Pavement
The rolldown tests were performed on relatively rough pavement. No holes or bumps, but the tar between the aggregate had washed away over decades of Seattle weather. Interestingly, high pressures generally did result in slightly higher speeds for some clincher tires. It’s not a lot, but it’s statistically significant.
The track tests were run on very smooth, newly laid asphalt pavement. There, we see the opposite. High pressures of 100-110 psi result in slightly lower speeds. How can we explain this? One hypothesis is that the tire deforms more on the rougher pavement to conform to the surface irregularities. At lower pressure, you create an imprint of the road surface in the tire as it rolls. At higher pressure, the tire bridges the gaps between the high points, and thus deforms less. On the smooth road, there aren’t any gaps to bridge, and so the high pressure loses its advantage.
Moderately high pressure = worst performance
On the smooth track, moderately-high pressure (100-110 psi) is worse than either lower or higher pressures. Why is that? Here is a possible explanation: As you increase the pressure, the suspension losses (vibrations) increase faster than the flexing of the tire (hysteresis) is reduced. So you lose performance as you increase pressure. At a certain point, the bike is vibrating as much as it can, but higher pressures still reduce the flexing of the tire. So from that point onward, higher pressures improve performance – until you end up back where you started at lower pressures.
Tubulars vs. Clinchers
What about the worse performance of tubulars at higher pressures? Tubulars derive much of their performance from their suppleness and low suspension losses. Increasing the pressure increases vibrations faster than it reduces the flexing of the tires. These explanations are just hypotheses – our best guesses to explain what we see. The data itself – higher pressures don’t lead to improved performance – is beyond doubt.
hawaii_01
Take-Home Message
For most riders, the take-home message is simply this: As long as you inflate your tires enough that they are safe to ride, tire pressure doesn’t matter much. Find a pressure that feels good when cornering, and ride your tires at that pressure. When in doubt, let out some air – you’ll be more comfortable and have better cornering grip. (If you ride narrow tires, beware of pinch flats, though!)
If you worry about the last bit of performance, then you can try to use the data above to tease out that last 2%. On smooth roads, low tire pressures yield the best performance. On rough pavement that doesn’t have holes or bumps, increasing your pressure may make your tires a little bit faster. That may seem counter-intuitive, and of course, it also will be less comfortable. But if you are doing a short time trial on a country road, it may be worth considering. Ideally, you’d run a few experiments with a power meter to dial in your tire pressure for that particular road surface.
If you run tubular tires, you should definitely run them at relatively low pressures. This provides the best performance and the best comfort on all surfaces we’ve tested. As for me, I run my tires at relatively low pressures on all roads. My rides encompass a multitude of surfaces, and on truly bumpy roads, we’ve shown that lower pressures always are faster, because the bike bounces less. But that is a topic for another day…

Continue Reading

The Tire Pressure Revolution

reiter_road_to_index
Of all our research on tires, the most revolutionary finding is this: Tire pressure has almost no effect on a tire’s speed. We did not believe it at first, either, so we’ve tested it numerous times. It’s been confirmed numerous times, with different methodologies.
The real revolution is not how you use your pump… What has totally changed our riding are the wide, supple tires, which only work because of this new insight.
track_tire_test
First, let’s look at the data. Here is one experiment: We ran three different 25 mm tires (a supple clincher, a supple tubular and a harsher-riding clincher) at pressures from 4.5 and 9 bar (65 and 130 psi). These tests were done on very smooth asphalt (above), a surface where high pressures should offer the greatest advantages. The graphs below show the power required to ride the bike (above) with the tires at a constant speed of 27.8 km/h, but with different tire pressures.
tire_pressure
There is no relationship between tire pressure and performance in the tested range. (Lower and higher pressures are unsafe to ride.) The graph above shows some variation in power output (lower is better), but there is no trend. The CX tubular rolls fastest at 5.5 bar, the CX clincher is a little faster at 6 bar, while the Rubino is fastest at 9 bar, but almost as fast at 6.5 bar.
Take-home message: Don’t stress about tire pressure!
IMG_0397
This finding has revolutionized our understanding of tires. In the past, we all thought that higher tire pressures made tires roll faster. And that presented a problem for wide tires: A wider tire puts greater loads on the casing than a narrow one. To compensate, you have two choices:

  1. Beef up the casing, which makes the tire less supple and slower.
  2. Lower the pressure, which we thought made the tire slower.

No matter which route you took, then-available science predicted that your wider tire would be slower. It was a catch-22, and for the best performance, you stuck with narrow tires, where you could have a supple casing and high pressure at the same time.
But after realizing that tire pressure doesn’t matter for performance, we were able to explore new possibilities. If lowering the pressure does not make tires slower, you can make supple, wide tires. You run them at lower pressures, and you don’t give up any performance on smooth roads. On rough roads, you gain speed, because the tire (and you) bounce less. And on all roads, you are more comfortable. Instead of a catch-22, you have a win-win-win situation.
tires_comp_650_42
It’s this research that has led professional racers to adopt wider tires. They are up to 25 mm now. (Wider ones won’t fit on their bikes!) For the rest of us, there is no reason not to go wider. I now ride 42 mm tires at 3 bar (43 psi), knowing that they roll as fast as a 25 mm tire at 6 bar (85 psi) – or 9 bar (130 psi), for that matter.
fmb_tread
To get the most benefit out of these lower pressures, you need supple tires. A stiff sidewall takes more energy to flex, so the tire will be slower. And since the sidewall is stiffer, it also will be less comfortable. You could call it a “lose-lose” situation.
Professional racers have known this all along: As much as their equipment has changed over time, they’ve always ridden supple tires. They usually ride hand-made tubulars (above), but for the rest of us, supple, wide clincher tires now make it possible to enjoy the ride and speed of supple tires on any road.

Continue Reading

TPI and Tire Performance

IMG_0397
Tires with supple casings are faster, more comfortable and simply more fun to ride. Most cyclists know this, but how do you measure “suppleness”?
A measure that often is used to describe the quality of tires is “threads per inch” (TPI). The idea is that tires with higher thread counts usually have finer weaves that make these tires more supple.
The reality is more complex, and TPI is of limited use when comparing tires. Here is why:
1. How do you measure? Ideally, you look at the TPI of the casing fabric before it is made into the tire. Casing fabrics vary between 15 TPI for coarse utility tires to 120 TPI for very high-end tires.
What about the tires with 300 TPI or more? These makers count every layer of the tire. Most tires have three layers of overlapping casing, so by that method of counting, a 100 TPI fabric will make a 300 TPI tire. And if you added a fourth layer for added puncture protection, you’d make the tire slower, but you’d bump up the TPI to a record-setting 400! So if a tire makers claims a TPI of more than 130, you have to divide the number by 3 to get the TPI of the fabric.
2. What is the diameter of the threads? The reason high-TPI tires usually are more supple is that the threads are thinner. If you keep all things equal, thinner threads will mean more threads per inch. However, if you make your weave denser, you also get more threads per inch, but actually a stiffer casing.
Panaracer, who makes our Compass tires, offers a 120 TPI casing. However, they found that if they use the same super-fine threads, but space them out a little further, they get an even more supple, and even faster, tire. So the Compass Extralight tires use that casing, which only has 90 TPI.
If you go by TPI alone, the Extralight casing looks inferior, but it’s in fact the more supple, faster casing.
3. How much rubber? Fabrics with very thin threads are fragile. They have to be handled very carefully during production. Some makers of budget tires compensate for this by covering the fabric with more rubber, which protects the threads. Of course, this makes the casing stiffer, and thus less performing. So one maker’s 120 TPI casing may be a lot less supple than another maker’s 120 TPI casing.
4. What material is used for the threads? With hand-made FMB tubulars, you get a choice of cotton or silk threads. The silk is much more supple than the cotton (which already is more supple than most polyesters). Even among polyesters, there are great differences in the thread materials. It makes no sense to claim that a 90 TPI silk casing is less supple than a 100 TPI cotton casing.
These are just a few of the factors that determine the tire’s suppleness. Let’s compare two hypothetical tires:
Tire 1 uses a stiff and relatively large-diameter thread. The fabric has a super-dense weave and is slathered with rubber. The maker counts every layer of the casing, and thus arrives at a 300 TPI tire.
Tire 2 uses a supple, superfine thread, woven into a relatively loose weave. The manufacturer keeps the rubber coating to a minimum. They report the TPI of the casing fabric, and arrive at a 90 TPI tire.
It’s easy to see that the Tire 2 above is superior to Tire 1, even though it has less than 1/3 the TPI. Suppleness, like so many important things, is hard to quantify, but you’ll notice it when you ride the tires.
Acknowledgments: Thank you to the engineers from Panaracer, Francois Marie of FMB tires, and Challenge Tires for the information contained in this post.

Continue Reading

Optimizing Tire Tread

Compass_tread_pattern
Most tire manufacturers agree that supple sidewalls and a thin tread make a tire fast, but the role of the tread pattern remains poorly understood. Most modern tires have either a completely smooth tread (slicks) or a coarse tread pattern similar to car tires. Many high-performance tires are smooth with just a few large sipes. None of these tread patterns are optimized.
Car tires have tread mostly to prevent hydroplaning. With their wide, square profile, a layer of water can form between tire and road surface. The tread pattern forms channels so the water can be pushed out of the tire/road interface.
Bicycle tires do not hydroplane. Their contact patch is too small and too round for that. This means that car-inspired tread patterns are not necessary on bicycle tires. Does this mean that no tread pattern at all – a slick tire – is best? Any tread pattern reduces the amount of rubber on the road surface… In the lab, it does work that way: Slick tires grip best on smooth steel drums.
Real roads are not as smooth as steel drums. An optimized tire tread interlocks with the irregularities of the road surface to provide more grip than the pure friction between asphalt and rubber. This is especially noticeable in wet conditions, when the coefficient of friction is reduced by half, yet you can corner with about 70-80% of the speed you use on dry roads. (Unless the road surface is greasy…)
The ideal tire tread has as many interlocking points with the road surface as possible. The “file tread” found on many classic racing tires does this. The ribs are angled so they don’t deflect under the loads of cornering or braking.
Why do race cars use slick tires, and not a file tread? The reason is simple: It would be abraded the first time the car accelerates. However, bicycle tires don’t wear significantly on their shoulders – the part that touches the ground when you corner hard – so we can use a tread pattern that is optimized for grip without worrying about wear.
Each Compass tires has three distinct tread patterns, each designed for a specific purpose.

  • Center: Fine ribs serve as wear indicators. When the lines disappear, the tire is about half-worn. (The tread of our narrower tires is not wide enough for ribs, so small dots are used instead.)
  • Shoulders: When the bike leans over as you corner, the tire rolls on it shoulders. A chevron or “fine file” tread pattern optimized grip.
  • Edges: This part never touches the road (unless you crash). They serve only to protect the casing from punctures, so they don’t need any tread.

TireProfile-hi
Supple casings make tires faster, but a supple casing is of little use when it’s covered by thick tread rubber. The fastest tire would have just a minimal layer of tread rubber, and many “event” tires are made that way. Unfortunately, that means that they don’t have much rubber to wear down until they are too thin to use. At Compass Bicycles, we call these tires “pre-worn”.
Compass tires have a slightly thicker tread in the center. A little more material there doubles or even triples the life of your tire, while adding minimal weight and resistance. (On our widest 650B x 42 mm tire, the added tread weighs less than 50 grams.) Once you have ridden the tires for a few thousand miles, they’ll be as light as the “event tires”.
On the shoulders and edges, the tread does not wear. So we made it much thinner to keep the tire supple and reduce its weight. The tread extends far enough down the sidewall that the casing is protect when seen from above. Extending the tread further adds little protection, but makes the tire less supple and thus less comfortable and slower.
tires_comp_650_42
Another important factor is the tread rubber. This is an area where incredible progress has been made in recent decades. In the past, you could either have good grip or good durability. I used to ride Michelin’s Hi-Lite tires, which gripped well, but rarely lasted even 1000 miles (1600 km).
Compass tires use Panaracer’s best tread rubber, which is amazing. Our tires are among the grippiest you can find, yet I just got an e-mail from a 230-pound rider who got 3786 miles (6093 km) out of a set of our 26 mm-wide Cayuse Pass tires. The wider tires spread the wear over more rubber, so they last significantly longer. (Don’t try to set wear records, but replace your tires once they get thin. The risk of flats, or worse, blowouts, is not worth getting an extra few hundred miles out of a worn tire.)
Tread color is another important consideration. Modern colored treads no longer are the “death traps” they used to be, but especially in wet conditions, the grip of tires with colored treads – including the Grand Bois Hetres we sell – is not quite as good as that of black treads. That is why we offer only black tread.
Click here for more information about Compass tires.
Update 9/25/14: Roadbikerider.com just published a review of the Compass tires. Click here to read it.
 
 

Continue Reading

The Actual Width of Tires?

38_final_width
Sometimes we get an e-mail or a phone call from a customer asking, “I bought the Compass 32 mm tires, but they only measure 28.5 mm on my rims. Why is this?”
Decades ago, some tire makers cheated when stating tire widths. Why? To make their tires appear lighter than they really were. By selling a 25 mm tire as a 28 mm, they made the tire seem lighter than the competition’s tires, which actually were 3 mm wider.
That was long ago, and it’s not what is going on here. We label our tires as close to their actual width as possible. Here is why different people report different widths for their tires:

  1. It can be difficult to accurately measure the width of a supple tire.
  2. The casing of supple tires stretches for a few weeks or even months after they have been installed.
  3. Tire width depends on tire pressure and rim width. That means the actual width can be a little narrower or wider than the nominal width.

38_squeezed
I recently installed a set of Compass Barlow Pass Extralight 700C x 38 mm tires on a Bicycle Quarterly test bike. How wide are they really?
When you measure metal with calipers, you squeeze the calipers until they won’t go any further, and then read your measurement. If you compress the calipers on a rubber tire, the tire will deflect. In this case, I measured 34 mm. But that isn’t the actual width of the tire: If you tried to fit the tire into a frame with just enough clearance for 34 mm tires, it would rub.
38_iteration
Here is how you measure tire width: Open up your calipers in 0.5 mm increments. Check whether there is “play” between the caliper jaws and the tire. In the photo above, I am already at 35.5 mm, and the calipers still fit snugly on the tire.
38_new
At 36.5 mm, I am finally getting some wiggle. This means that the tire is just over 36 mm wide. That is the width when it’s new.
38_low_pressure
Two weeks later, I measured the tire again. It has stretched to 36.5 mm. I was surprised that it was still so narrow, until I checked the tire pressure. I had let the pressure drop to about 30 psi. How wide would the tire be at its maximum pressure?
38_final_width
I inflated the tire to 75 psi, and lo and behold, it now measured 37.5 mm. It probably will stretch a little more, and achieve its full 38 mm width before long. Of course, I wouldn’t ride it at that pressure (unless I put it on a tandem), so at the pressures I usually ride, the tire will be a tad narrower than its nominal width.
Should I inflate my tires to a higher pressure to make them wider? No, that doesn’t make sense. Your tire’s comfort and performance is determined by the tire width at the contact patch, which gets larger at lower pressure. Putting more air than necessary into the tire defeats the purpose, even if it makes the tire wider where it does not touch the ground.
For narrower tires, rim width also plays a role. The Compass Stampede Pass tires measure about 31 mm on a 20 mm-wide rim, like a Mavic MA-2, but 33 mm wide on a 23 mm-wide rim, like a Grand Bois rim. For wider tires, this is less of a factor, since all the rims we use are narrow when compared to the wide tire.
gravel_road
In any case, our testing has shown that the material and construction of the casing are more important for comfort and speed than a millimeter or two in width. When you put a set of supple Compass tires on your bike, you’ll notice a huge difference in how the bike feels and performs.
And when you buy your next bike, make sure to spec a frame that provides ample tire width. On my own bikes, I am not too concerned whether the tires measure 39 or 41.5 mm. Either is ample for most of the riding I do.
Further reading: How Wide a Tire Can I Run?

Continue Reading

How much faster are supple tires?

willapa_fleche
Improving your tires can make the biggest impact in the speed of your bike (apart from changing the motor!). The difference is especially pronounced for slower riders, whose wind resistance is less than that of faster riders.
Most cyclists know that supple tires make you faster on your bike. But so do ceramic bearings in your derailleur pulleys. The important question is: “How much faster?” For ceramic bearings, the difference is too small to notice on the road, because standard ball bearings already have close to zero resistance.
For supple tires, the difference is much greater. If you have a hard time staying with a group, changing your tires to a faster model may help you avoid getting dropped. And if you get close to the time limit in brevets, faster tires can provide you with a significant time cushion, so that a flat tire or a slight detour due to misreading the route sheet no longer results in a DNF.
Here is a comparison between three tires from Bicycle Quarterly‘s tire tests. These are all marketed as performance tires, and none of them have puncture-proof layers that would further slow them down.

  • Vittoria Open CX Corsa 700C x 25 mm
  • Grand Bois Cyprès (standard casing) 700C x 32 mm
  • Rivendell Rolly-Poly 700C x 27 mm

rolldown
Our first tests were rolldown tests on relatively rough pavement, like you typically find on American backroads. The speed was between 23 and 25 km/h (13.5 – 15.5 mph).
On this surface, the fastest tire rolls 13.5% faster than the slowest. That is a huge difference. Imagine going 15 mph with the slower tire, and on your next ride, after changing your tires, riding at 17 mph with the same effort. During a century ride, you’d be 45 minutes faster!
track_power
We also tested these (and many other) tires on a very smooth asphalt surface at constant speed with a Power Meter. The speed was higher (27.9 km/h; 17.3 mph), and the ultra-smooth surface reduced the vibrations. However, even under these “ideal” conditions, the rider on the slowest tire had to put out 13.5% more power to keep up with the rider on the fastest tire. That can make the difference between “hanging with a group” and getting dropped within a few miles.
If you calculate the speed difference for the same power output, it’s 5%. (Wind resistance going up exponentially with speed, so you need 13.5% more power to increase your speed by 5% to stay with the rider on the faster tires.)
As you can see, supple tires make the greatest difference on rougher surfaces, and at lower speeds. But even at high speeds, make the largest difference in the performance of your bike. For comparison, aero wheels make you about 1% faster. And when you are drafting, your wind resistance goes down, so rolling resistance becomes even more important. That is why the pros always have ridden supple tires.
Does this mean we all should ride Vittoria CX tires? Not exactly. The CX is optimized for ultimate performance, and it has a very thin tread. This means it will wear out quickly and suffer more punctures on the way. If you are racing or riding a timed event, these compromises may be worth making. For everyday use, it often makes sense to give up some speed to obtain twice as much service life and fewer punctures.
The Grand Bois Cyprès is designed as an all-round tire. It has a thicker tread that will last thousands of miles. It will get faster as it wears. The Grand Bois also has a sturdier casing that resists sidewall cuts better. As a result, it rolls a little slower. (Disclosure: Compass Bicycles sells Grand Bois tires.)
The Rivendell Rolly-Poly has an ultra-tough casing that provides peace of mind when you ride through debris and are afraid of cutting your tire’s sidewalls. This may be overkill for most riders. The more rigid casing slows the tire down significantly.
tires_comp_700_28
When we designed our Compass tires, we started with the Grand Bois tires, and then optimized the performance further, without making the tires into “event” tires that are not very suitable for everyday riding. We reduced the tread thickness on the shoulders of the tire, where it does not wear out, but kept it the same in the middle, where it wears.
For the Extralight models, we used a casing that is significantly more supple than the “standard” casing shown in the test results above. We haven’t measured the performance under controlled conditions yet, but our (and others’) on-the-road experience suggests that they are significantly faster than the standard models.
Tires really make a big difference. When I switched from tires with stiff sidewalls to supple ones, not only did I set many personal bests on long rides, but I also found that I could rest while drafting, whereas before, I was working hard just to hang on.
Take our Flèche team in the photo at the top: If one of us had significantly slower tires than the others, he would have to be much stronger just to keep up. We’d rather have the stronger rider take longer pulls at the front!
IMG_0397
What if you don’t care about speed? Supple tires also are much more comfortable. And they just feel different, making cycling much more fun. To me, that is the most important difference, and why I ride them on all my bikes.
Further reading:

Continue Reading

The Art of Compromise

compass_babyshoe
It may be popular to talk about “no-compromise” products, but the reality is that the best products involve a careful balance of features and properties. Take our new Compass tires…
ScaleWideNarrowTire
We could have made them lighter!
The only place to remove material is in the middle of the tread. We might save up to 50 grams on the 650B x 42 mm Babyshoe Pass, but the tire would wear out much faster.
So we removed all the weight we could, but left just the right amount of tread to provide a long service life.
aero_tuck
We could have made them faster!
A thinner tread flexes less, reducing the rolling resistance slightly. If we had reduced the tread thickness in the center, we might have increased the speed by up to 1%. The difference is very small, and it comes at the expense of longevity and puncture resistance.
We already use the most supple casing available. Our research has shown that the casing, more than anything else, influences the speed and comfort of a tire.
Our tires will be as fast and as light as “event” tires once you have ridden them for a few thousand miles. A friend of mine calls other companies’ super-thin event tires “pre-worn.”
mtb_trail
We could have made them sturdier!
Reinforcing the tire sidewalls, adding puncture-proof belts or making the tread thicker all will make the tire sturdier. The downside is that the tires would ride harshly and roll slower.
We decided that our tires needed to hold up in most off-pavement conditions. We have tested them on gravel roads and even moderate mountain bike trails (above) without problems. For us, that makes them sturdy enough.
Hint: Wider tires are inflated to lower pressures, so they roll over debris that would puncture a narrower tire. You get less flats that way.
worn_tire
We could have made them last longer!
A thicker tread gives you more rubber to wear down before you have to replace the tire. However, after a while, the tire becomes “squared off” and no longer corners well. The thicker tread also increases the tire’s rolling resistance. (The Grand Bois Hetre in the photo above may look squared off, but it’s actually still nice and round after about 10,000 km/6000 miles.)
We decided to make our tread thick enough that it will last thousands of miles, but not so thick that it will square off before wearing out. We feel that is a good compromise.
Hint: Wider tires spread the wear over more rubber and last longer.
red_green_tires
We could have made them more colorful!
Our on-the-road experience has shown that colored rubber does not grip as well as black rubber, especially on wet roads. So our Compass tires use black tread rubber for optimum handling and safety, but the sidewalls are available in both tan and black, depending on your taste.
Fortunately, there are some things where compromise is not necessary. Handling is one of them.
descent_blewitt
We could NOT have made them corner better!
We spent a lot of time researching tire treads, before selecting a pattern that offers optimum grip in wet and dry conditions. The tread pattern along with the grippy yet durable rubber make our tires corner better than any tire we have tried.
reiter_road_to_index
We made many compromises when we designed our tires. We think they are the right compromises to provide you with tires that offer a maximum of performance, comfort and fun, while being suitable for everyday riding, commuting and even gravel roads. We are proud of the result, and we are glad to hear that others are enjoying these tires as much as we do.
Click here to find out more about our Compass tires.

Continue Reading

Feedback on the new Compass Tires

barlow_pass_in_britain
As we get the first feedback from riders about our new Compass tires, it’s nice to hear that others enjoy them as much as we do. Here are a few samples of unsolicited feedback:
“I used the new Barlow Pass tyres on a route that included miles of rough railway trackbed. They make a big difference! A lovely ride both on and off road, I realise what I’ve been missing after years of heavy-duty Schwalbes.” – Tim Bird, who took the photo above.
“Thanks for making available the finest clincher tires I’ve ridden on in my 45 years of cycling!” – a customer who placed an order for another 8 tires!
“These new tires feel like they were designed for racing. It seems like they have better rolling resistance (as if I were running in a lower gear) and with better cornering that the Hetre XLs.” – a customer who wondered whether we’d discovered an extra-grippy rubber compound for the tread.
“Recently I have been looking at everyone’s rubber trying to find that perfect tire. You have pretty much delivered everything I had in mind.” – a former tire developer for a big U.S bike company.
“I have ridden about 130 miles so far on the 700×38 Barlow Pass Superlight tires. They have made my mid-1980’s Miyata 1000 touring bike much more enjoyable and fun to ride. Thanks.”
“I have been commuting on the Barlow pass tires for a week or two and am really happy with them. They roll faster and smooth out the bumps more than my previous set of Schwalbe Marathon Racers.”
“Oh my gosh I just love those tires!”
It’s nice to see that others share our enthusiasm and appreciate all the research and testing that went into designing these tires. Click here to find out more about our Compass tires.

Continue Reading

Tires: How Wide is too Wide?

track_tire_test
How wide a tire is too wide for optimum performance? Our research shows that wider tires don’t give up anything on smooth roads, and gain a significant advantage on rough roads. This has been shown for tires up to 31 mm wide.
It’s now a well-established fact that wider tires roll faster than narrow ones. Professional racers now use 25 mm tires, which are 20% wider than the tires that most racers used just 20 years ago. Will this trend continue? Can we expect racers to be on 30 mm tires in the future? No matter what the pros do – they are influenced by many factors that have little to do with science – the real question is: Up to what point are wider tires faster?
5208508437_58d18286d0
It is obvious that the tires in the photo above will not roll very fast. Clearly, at some point, the performance benefits of wider tires (shorter contact patch and thus smaller hysteretic losses; reduced suspension losses) will be outweighed by the disadvantages of extra weight and increased wind resistance.
Test_Woodland
In our original tire tests (above), we tested the same tires in 21, 23 and 25 mm widths on a moderately rough “backroad” surface. The results were clear: The 21 mm tires were slowest, 23 mm was in the middle, and 25 mm tires were fastest. The speed difference between 21 and 25 mm tires amounted to about 2.5%. Over a typical 200 km brevet, I would gain about 11 minutes. It’s not huge, but significant. These results appear to have prompted the current trend of racers using wider tires.
What about tires that are wider than 25 mm?
RumbleStrip
Our testing on rumble strips showed that on very rough surfaces (the equivalent of cobblestones), 42 mm tires are faster than 25 mm tires. However, few of us ride all the time on cobblestones, and what we want to know is whether we give up anything on smooth roads when riding wider tires.
To determine this, we tested Grand Bois tires in 26, 29 and 31 mm widths on a super-smooth asphalt surface (see photo at the top of the post). The results were the same for all three tires. On the smoothest asphalt, you don’t gain anything by going to tires wider than 25 mm, but you also don’t give up anything.
Those tests were run at 25 km/h (16 mph). At higher speeds, the aerodynamic disadvantages of wider tires might be greater. Does that mean that 31 mm tires are a fine choice for riding at moderate speeds, but that you would be better off on 25 mm tires when you go faster?
drafting
We tested both 25 and 31 mm-wide tires in the wind tunnel. The result: The raw data showed a 1% increase in wind resistance for the wider tires, but the results weren’t statistically significant. Even if we accept them at face value, the added wind resistance is too small to make a noticeable difference. For example, at a very high speed of 40 km/h, decreasing your wind resistance by 1% only adds 0.4% (or 0.14 km/h) to your speed.
What about the heavier weight of wider tires blunting the acceleration of your bike? That doesn’t appear to be a major factor either, since wheel weight is less important than many riders believe. (See this recent post for a discussion of wheel weight on professional racers’ bikes.) If you use smaller 650B wheels, you make up some of the greater weight of a wider tire through a lighter rim.
All this data shows that 31 mm tires roll as fast as 25 mm tires, even on very smooth roads. And when the roads get rougher, the wider tires roll faster.
rando_ti
What about even wider tires? Our on-the-road experience suggests that even 42 mm-wide tires do not roll slower than 25 mm tires (above), but without rigorous testing under controlled conditions, we can not say for sure. We hope to test this soon.
Of course, there are other reasons beyond performance to ride wider tires. You gain comfort. You will incur fewer flats, since you run wider tires at lower pressures, so they roll over obstacles that would get hammered into narrower tires. You’ll be safer, since a wider tire will be less affected by small cracks and railroad tracks.
Most of all, you’ll be enticed to go on small roads that have great scenery and little traffic – roads you might have avoided with narrow tires because the pavement tends to be rough. With more comfortable tires, you can even enjoy roads with no pavement at all!
To answer the question in the headline: Even 42 mm does not yet appear to be “too wide.” Tires wider than that are hard to fit into the rear triangle of a bike without compromising performance (tread/Q factor, chainstay length), so perhaps frame design more than other factors limit the maximum tire width on a performance bike.
Wide tires are one of the few things with a lot of advantages, but very few disadvantages. (There are some downsides to wide tires, which we’ve mentioned here.)
For all our tests, we used tires that had the same casing material, tread pattern, etc., to isolate the effects of tire width. Of course, there are many other factors that influence tire performance, and width is only one important factor. (A wide “touring” tire with a stiff puncture-resistant casing is much slower than a narrow “performance” tire with a supple casing.)
This post is just a summary of the research. The original data and much more detail were published in Bicycle Quarterly. Here are a few resources for further reading:

Continue Reading

Tire Wipers

tire_saver
Many cyclists are tempted by the performance and comfort of supple tires, but they are afraid that they might get too many flats without puncture-resistant belts and reinforced sidewalls. Tire Wipers improve the flat resistance of your tires without detracting from their comfort and performance.
Few foreign objects are so large and so sharp that they puncture the tire upon first impact. Most require several revolutions of the wheel to work their way through the tire. When you roll over debris, you often hear the “pock, pock, pock” as the debris gets pushed into the tire with each wheel revolution, followed by a “pshhhh” as the tube deflates.
If you could get rid of the debris after it is picked up, but before it gets hammered into the tire, you could prevent a good number of flats. Enter Tire Wipers – small wires that lightly rub your tires and remove debris before it gets lodged in the tire.
tires_wipers1
Do they work? Flat tires are so random that this is hard to quantify, but the general consensus is that they do prevent many, if not all, punctures.
Tire Wipers have been hard to find in recent years, but Scott Gabriel is making them again. Compass Bicycles carries them, in two models. One attaches to the brakes of bikes without fenders, the other is installed at the exit (front edge) of your fenders (above). Click here for more information.

Continue Reading

How Wide a Tire Can I Run?

Fork_clearance

Many cyclists want to ride on wider tires, but are limited by the clearances of their bikes. So they want to use the widest tires their bike can fit. How do you determine your bike’s maximum tire width?

You need a set of calipers (below). If you don’t have any, bike shops have them. Please leave a generous tip if you ask a shop mechanic to help you with this!

calipers

Measure the width of your current tires. Be careful not to pinch the tire. Instead, increase the opening of the calipers by 0.5 mm increments, and check whether the opening has play when it is slipped over the tire. (The calipers “rattle” when you move them.) When this happens, the calipers are set just a tad larger than the actual width of your tires. Use this measurement as your current tire width.

If you pinch the tire with the calipers, you may get a measurement that is up to 2 mm narrower. Also don’t use the width that is printed on the side of the tire. More likely than not, it’s inaccurate.

chainstay_clearance

Then check all around how much clearance you have. Most important are:

  • fork crown
  • brake calipers (front and rear): squeeze your brakes to get the clearance when braking
  • chainstays
  • seatstays can limit the clearances on some bikes.
  • fenders: often, you can adjust the fenders to eliminate a tight spot.

I recommend a minimum of 3 mm clearance between your tires and the closest part of your bike. Any less, and you run the risk of having your tire rub, under hard acceleration or if the wheel develops a slight wobble.

To calculate your maximum tire width, start with the smallest clearance between your existing tire and bike. Then deduct the minimum clearance, 3 mm, to get the existing available clearance for your wider tire. Multiply this by 2 (you have that much room on both sides of the tire), add the current tire width, and you get the maximum tire width.

Example: Your current tires are 29 mm wide. You have 5 mm clearance at the tightest spot. That leaves 2 mm available clearance. You can run 4 mm wider tires than your current ones. You maximum tire width is 33 mm.

This assumes that your new tires have a similar height-to-width ratio as your existing ones. Some inexpensive tires can be much taller than they are wide, but high-end tires usually are relatively round, and this formula works well.

If you find yourself between two available tire sizes, I suggest you use the narrower tire. High-end tires tend to expand over time as the casing “relaxes,” and you don’t want your tire to rub every time you rise out of the saddle and flex your wheel. If you find that you still have extra clearance, you can go up one more size when the new tires wear out.

By the way, the bike in the photos does not appear to have extra clearance, so if your bike looks like that, you probably should stick with the tire width you have. You still can improve the ride and performance of your bike by using more supple tires with higher-quality casings.

Photo credit: Ernie Fong.

Continue Reading

Hutchinson 650B x 32 mm Tires


Compass Bicycles now carries the Hutchinson “Confrérie des 650” tire. The Confrérie des 650 was created by French riders who loved their 650B bikes. They were concerned that the wheel size might become extinct, leaving them without rims and tires for their bikes. So they formed the Confrérie and began working with manufacturers to offer 650B tires.
Since its inception, the Confrérie has focused on 32 mm-wide tires, because most French 650B bikes of the 1960s-80s used this size, for example, this lovely 1965 René Herse that recently sold on eBay. The first tire the Confrérie created was the Michelin Megamium. This was a utilitarian tire, but it was enough to keep many bikes on the road. In recent years, the increasing popularity of 650B tires in North America and Japan has brought many new and excellent 650B tires to the market, and there is no longer any risk of the wheel size becoming extinct. However, the Confrérie was wary of depending on others for their supplies. So when Michelin decided to stop making the 650B Megamium, the Confrérie worked with Hutchinson to make a replacement.
The result is the new Hutchinson 650B x 32 mm tire. Unlike the relatively narrow Megamium, it measures a true 32 mm wide. Hutchinson used their top-of-the-line racing casing for this tire, so it rolls very smoothly and absorbs shock very well. It is hard to estimate puncture resistance, but it appears to be fine in that respect. As a modern tire, the Hutchinson is black with reflective silver sidewalls. Whether you like it or not is a matter of taste – I prefer the more classic appearance of other 650B tires. It’s hard to dislike the light weight of the Hutchinson: At 267 g, it is the lightest 650B tire available today.
I feel that the Hutchinson is an excellent tire that adds significantly to the appeal of the 650B wheel size. To make it available in North America, Compass Bicycles now carries it in our tire program. More information is here.

Continue Reading

Mounting Tires on Rims with Deep Wells


Sometimes we get a call or an e-mail from a frustrated customer: “I have a brand-new set of your tires, and both wobble when I mount them on my rims.” In most cases, it is not the tires’ fault. Usually the problem stems from the difficulty of mounting tires on poorly designed rims. However, there are some tricks for mounting tires on these rims.
Above, you see a correctly mounted tire. Most tires made today have a line molded into the sidewall (arrows). This line must be visible all around the tire, and parallel to the rim edge. The line not only helps seat the tire, it also serves as a visual indicator that the tire is concentric with the rim. (Usually, the line is a little higher above the rim, but always parallel to the rim edge.)

Above are three 700C rims, which all have the same outer diameter. However, the cross sections show that they are very different on the inside. Rim 1 is a proven design. Rim 2 has a shallower well (the place where the tire mounts). Rim 3 has a very deep well. Tires seat differently on each of these rims.

When you mount a tire, the tire beads need to go over the rim’s hook (above; the foam is used to hold the tire in shape). Tire beads are what holds the tire on the rim. They don’t stretch much – otherwise, the tire would just blow off the rim when you inflate it. The well of the rim has a curved bed. When you mount the tire, the tire beads drop into the center of the rim’s well bed. This provides enough slack to get the last bit of tire bead over the rim’s hook on the opposite side. As you inflate the tire, the beads slide up the rim’s curved well bed until they seat tightly underneath the rim’s hooks.
The photo above shows Rim 1. The tire’s beads fit perfectly onto the well bed and underneath the hook. The tire will seat concentrically by itself as you inflate it. The bead seat diameter is 622 mm, as industry standards specify (ETRTO). This is how rims should work.

Rim 2 has a shallower well. The bead seat diameter is 624 mm, which makes the well bed higher than the standard 622mm. To seat correctly, the tire has to stretch by 2 mm in diameter. This translates into 6.5 mm (1/4″) along the tire’s inner circumference, which is a lot of stretch for a tire bead. Often, the beads don’t stretch enough, and don’t quite reach the rim walls (arrow). Then the tire will wobble on the rim. Putting talc (baby powder) on the tire bead may help it slide into position. A very thin and slippery rim tape also can be helpful.
The high well bed also makes the tire difficult to remove: It is difficult to insert a tire lever underneath the tire bead, because it is stretched so tight onto the rim.

Rim 3 has a very deep well. The tire is not supported by the well bed at all (arrows). The tire has to float. When you inflate this tire, it cannot just slide into position on the well bed. You will have to manipulate the tire until it is seated correctly.
Unfortunately, several common rims for wider tires, including the Velocity Synergy, several Velo-Orange models, and the no-longer-available Grand Bois, have overly deep wells. This makes mounting tires difficult. The sole advantage is that the tires come off the rim easily.
On their 650B rims, Synergy tried to “fix” the problem of poorly seating tires by increasing the overall rim diameter. In my experience, this has made things worse, because now the hook is in the wrong place. There is nothing to locate the tire: The well still is too deep, so the tire cannot sit on the well bed. And the hook is too high, so the tire cannot sit underneath the hook.
If you have rims with wells that are too deep on your bike, there are some tricks for mounting tires on them. There even is a “fix” that can overcome the problem of the overly deep wells to a large degree.

On all rims, even well-designed ones, tires often don’t seat well at the valve. The tube is reinforced here, making it stiffer, and it sometimes gets caught under the tire bead. Above, you see how the molded-in line moves away from the rim at the valve. (Often, this is more pronounced.) Not only will this cause the tire to wobble, but if the tube is trapped under the beat, it can chafe until you get a flat tire.

With the tube barely inflated (~5 psi), push the valve stem inward as far as you can. This usually frees the part of the inner tube that is trapped.

Harder to fix is the problem shown above: The line that is molded into the tire sidewall disappears into the rim (arrow). This often happens on rims where the wells are too deep, such as the Synergy Velocity shown here. (The Grand Bois rims we used to sell unfortunately were not much better.) It also can happen if the well is too shallow, and the tire bead does not contact the rim sidewall.

Push the tire to get it into the right place. Inflate it to about 15 psi, and use both hands to push it away from you, until the molded line appears. Go around the tire on both sides until the molded line is visible everywhere and parallel to the rim edge. This takes patience. It can be frustrating, and it’s the last thing you want to do when you have a flat on the road, and all your friends are waiting for you to get back on the road.

To address the problem of the overly deep wells, you can add two layers of rim tape (or handlebar tape, which is the correct width for 23 mm-wide rims). This raises the bottom of the well. Now the tire should seat correctly without as much manipulation.
Do not ride a poorly seated tire! The tire could come off the rim and cause a crash.
Of course, it would be nice to have correctly designed rims, where the tires seat automatically as you inflate the tubes.
Update 3/19/2014: Grand Bois has redesigned their rims with a shallower well, so they fit the tires properly. The new rims are in stock.

Continue Reading

The Downsides of Wide Tires


Since we have published a post about “The Dangers of Narrow Tires,” it is only fair that we look at the other side of the coin. What are the disadvantages (or even dangers?) of wider tires? I can think of a few:
– Weight: A wider tire and a wider tube always will be heavier than a narrow tire. The scale above shows the difference. On the left is a 650B x 42 mm tire. It weighs 410 g. With the same casing, the 700C x 23 mm tire on the right weighs just 220 g.
If you take the difference (190 g), add the extra weight of the larger tube (37 g) and multiply by 2, you get a weight difference of 454 g, or almost exactly a pound. (You probably also will use a wider rim, but the smaller diameter of the 650B wheel actually makes for a slightly lighter wheel.)
A full pound sounds like a lot, but it is less than a waterbottle. Does adding a second water bottle make your bike noticeably slower?
What about the importance of rotating weight? Thanks to the smaller wheel diameter of a 650B wheel, the rotational inertia of the 42 mm-wide 650B wheel-and-tire is actually the same as that of a 700C x 28 mm wheel/tire. So the difference there is negligible.
[youtube http://www.youtube.com/watch?v=8pzc2aYVFEg?rel=0&w=425&h=349]
– Shimmy: Shimmy is a problem with many causes and solutions. One factor among many are wide and supple tires: They can exacerbate shimmy on some bikes.

However, there are many bikes with wide tires that do not shimmy. And some bikes with narrow and medium-width tires shimmy (see video above, the bike shimmied even without my slapping my thighs). Still, it’s harder to make a bike with wide tires that doesn’t shimmy.

– Appearance: Some bikes just look wrong with wide tires. The iconic 1980s Cinelli Supercorsa (above) would not look right with 42 mm-wide tires. Riding bikes is not just about performance, but also aesthetics, and many riders prefer the slim appearance of a classic racing bike. (Photo: speedbicycles.ch)
And if you show up to a group ride with wide tires, you’ll have many people give you their well-meaning advice: “You need narrow tires if you want to go fast.” If you’d rather fit in, a wide-tired bike may not be for you.

– Availability: Few performance bikes are designed for wide tires. The image above shows the “Performance Bike” categories from a big manufacturer. You have a choice between more than ten types of performance bikes, but all have narrow tires.
Unless you can afford a custom frame, your choices for wide-tire road bikes mostly are limited to touring, commuting and hybrid bikes with overbuilt frames that may not be ideal for spirited riding.
Update 06/2016: Wow, this has changed tremendously since this post was written in 2012: Today, there are dozens of “gravel” and “adventure” models available even in mainstream bike stores.

– Tire choice. Narrow high-performance tires are available at every good bicycle shop. They are made by numerous manufacturers. Wide high-performance tires can be harder to find.
All those disadvantages are real and worth considering. For us, the disadvantages of wider tires are outweighed by the advantages:

  • Higher speed on rough surfaces, equal speed on smooth surfaces.
  • Fewer flats because wider tires run at lower pressures.
  • Longer wear because the wear is distributed over a larger contact patch.
  • Greater safety as tracks, cracks and holes no longer pose a serious risk.
  • Greater comfort and enjoyment, especially when riding on poorly surfaced backroads.


Just putting wide “touring” tires on your bike won’t transform it into a capable “Allroad” machine. A few factors are key to a nimble, fast bike with wide tires:

  • Supple tires: Most wide tires on the market are utility tires. Their sidewalls are not supple, and they lack both speed and comfort.
  • 650B wheels: Reducing the wheel size retains the nimble handling of a good racing bike. With very wide 700C tires, a bike becomes too stable to offer the sensations of a good performance bike.
  • Needle-bearing headset: It acts like a steering damper and greatly reduces the risk that your bike will suffer from shimmy.
  • Performance frame: The frame and its flex characteristics affect how the bike feels. To get the performance and feel of a racing bike, you need a frame with similar flex characteristics, and not a hybrid or touring bike.
  • Optimized geometry: Wide tires affect a bike’s steering. The geometry should be adjusted to get a surefooted, yet nimble bike.

You can obtain many of the advantages of wide tires simply by putting the widest tires that fit on your existing bike. My old Alex Singer was designed for 25 mm-wide tires, but I managed to fit 32 mm tires with adequate clearances. (I had to replace the fenders with a wider model.)
32 mm is a good compromise, but not as wide as I would like. My new bike with its 42 mm-wide tires (above) has shown me that the advantages of wide tires are best enjoyed with a new bike designed specifically for the tires you want to use. I now regret not having made the switch sooner.
What are your thoughts about tire width? Which tires do you ride now, and which tires will your next bike use?

Continue Reading

The Dangers of Narrow Tires


It is unfortunate that most “road” and even “hybrid” bikes are sold with tires so narrow that you cannot cross streetcar tracks at an oblique angle without risking a fall.
The Seattle Times reported recently about a rail line that crosses a city street not far from my house. “A bicyclist falls there daily,” the article reports. A business owner at the tracks found that “bike wrecks are so constant he keeps a first-aid kit at his front door.”
Over the past decade, there were 66 crashes serious enough to call out the fire department. Then there are the accidents on Seattle’s drawbridges, where cyclists fall into one-inch-wide cracks, sometimes with horrific consequences. There has been much talk about what could be done to make these places safer for cyclists, but gaps and tracks simply are part of the urban landscape in which we cycle.

I know that a skilled rider can bunny-hop across tracks and cracks, no matter at what angle they run. However, the fact is that many people ride bikes who are not that skilled. Nor should they need to be.
With the 42 mm-wide tires of my Urban Bike, I have experimented (at low speed) with the gap next to the rails. Even when crossing the tracks at a very shallow angle, the tires just rolled over the gap.
Since we cannot eliminate tracks and cracks from all roads, why don’t we fit 42 mm tires to the bikes that are sold to most cyclists? Wider tires would make cycling much safer. Besides, the current research indicates that wide tires are at least as fast as narrow tires. In fact, I never felt that I was handicapped during Paris-Brest-Paris last week by the 42 mm tires on my new randonneur bike. Of course, bikes with narrow tires would still be available for enthusiasts who really like the look and feel of narrow tires – but they’d come with warning labels.

Continue Reading

Preventing Flat Tires


Every cyclist knows the sensation: You ride along, feeling at one with your bike and the world. Suddenly you notice your tire going soft, often accompanied by a hissing sound. Like Icarus, who flew too high and got singed by the sun, your euphoria is dashed as you come to a wobbling halt on the side of the road.
Unlike Icarus, who perished as he lost his feathers, flat tires are merely inconvenient. In the video below, Mark shows how to change a tire in less than 90 seconds.
[youtube http://www.youtube.com/watch?v=6bWNOLuEBag?rel=0&w=425&h=349]
Even though you need some additional time to find the debris that caused the flat in the first place, a flat tire needn’t keep you off the bike for long. Nonetheless, we all would like to avoid flat tires as much as possible.
There are two main causes for flat tires. The first are pinch-flats, when your tire deflects so much upon hitting an obstacle that the tube gets pinched between obstacle and rim. The tube punctures, and sometimes your rim dents as well. (The photo below is from Paris-Roubaix, where racers use tubular tires, which are less likely to pinch-flat.)

If you suffer from pinch flats, raise the pressure of your tires. If your pressure already is at the recommended value, then your tires are too narrow for your weight and the road surface. With wide tires, pinch flats no longer are a cause for concern.
The second, more common, cause for flat tires is a puncture. Sharp objects work their way through the tire tread until they puncture the tube inside. There are three ways to reduce the incidence of punctures:

  • Avoidance: Don’t ride over debris that will puncture your tires.
  • Removal: Remove debris before it can get lodged in your tires.
  • Barrier: Introduce barriers that prevent debris from puncturing your tires.

Avoidance is why some riders have far fewer flats than others, even on the same roads and with the same tires. Debris accumulates especially on the sides of major highways. In the main traffic lanes, cars displace the debris until it ends up in the places where cars rarely tread – usually the side of the road or the shoulder, but also some spots at intersections.
If you ride in the traffic lane, you automatically avoid most debris. On busy highways, this is not an option, but at night or on lightly trafficked roads, there is no need to ride on the shoulder. On backroads without shoulders, you ride in the traffic lanes anyhow, greatly reducing your risk of flat tires. Check your maps and see whether you can avoid major highways, not only to reduce your risk of flat tires, but also for a more enjoyable ride. If you have to ride on the highway, don’t ride on the shoulder unless there is significant traffic. In the city, don’t hug the curb, where debris accumulates.
No matter where you ride, scan the road ahead. When you see debris, give it a wide berth. Debris to avoid includes:

  • Gravel left over from winter snowfalls. Freshly crushed gravel contains sharp rock shards that can puncture most tires. Gravel roads rarely see flats, though, perhaps because the gravel’s sharp edges are worn off as it is moved around when the road is built.
  • Glass. Bottle glass is sharper than the glass from broken car windows.
  • Exploded truck tires. Their insidious steel wires will work their way through most tires.
  • Plants with thorns that overgrow the pavement.

If you see debris up ahead on the shoulder of a highway, check whether traffic is clear, and if it is safe, ride in the main traffic lane for a few hundred feet. Debris tends to spread “downstream” from its source, as it gets moved by vehicles and their slipstream.

Debris removal can prevent many flats. Many racers wipe their tires with their gloves after riding through debris. More effective are “tire wipers” (see photo above), which also work on bikes with fenders. The wires of tire wipers very lightly brush the tire tread. They scrape off debris before it gets hammered into the tire as it rotates. When I raced on tubular tires, I used tire wipers (also called “tire savers”), and had only one flat in 4 years. That flat occurred when the wire of my tire wiper had moved and no longer brushed the tire. I have been thinking of putting tire wipers on my bike, but I have so few flats that it hardly seems worth while.

Barriers can prevent some debris from penetrating your tires. Puncture-resistant belts are effective against glass, because the glass gets pulverized between the belt and the road, rather than hammered into the tube. Sharp flints do not give up so easily, and usually penetrate the “puncture-resistant” belt all the same, just taking a bit longer to puncture the tube. Some tire manufacturers have increased the thickness of their tread so much that many obstacles no longer can get through, but remain stuck inside (see above). Unfortunately, extra belts and thicker tread make tires less supple, greatly reducing their comfort and speed.
Another way of creating a barrier is making the tire rubber itself harder to puncture. Many professional racers “age” their tires before they use them. Lance Armstrong famously had a mechanic with a cellar full of tires. As the natural rubber used in many high-end tires cures more, it is supposed to get more puncture-resistant. Does it really work? It’s hard to say, because flats can be random. However, it appears that when I ride on tires that have been manufactured recently, I get more flats than if I ride tires from a batch made a year or two ago. For Paris-Brest-Paris, I have stashed away a few tires, just in case.
Conclusion
I recommend avoidance as a first line of defense, with tire wipers as a backup in case you have too many flats. Both methods do not detract from the performance and feel of your tires. Aging your tires for a year or two may make them more puncture-resistant, and it doesn’t hurt.
Barriers are a good idea only if you suffer from a very large number of flats, and everything else has failed. Icarus may have soared too high, but without wings, he would had stayed on the ground and not got anywhere, either. To me, riding on puncture-resistant tires is like trying to fly with clipped wings. I prefer to fix a flat every couple of months.
Update (7/1/2013): Compass Bicycles now sells Tire Wipers.

Continue Reading

Science and Bicycles 1: Tires and Pressure


Most cyclists are interested in improving their bike’s performance, because rolling along at considerable speed while expending relatively little effort is one of the great appeals of cycling. Before you can improve your bike’s performance, you need to know what makes your bike faster, and that is where science comes in. Science is a fascinating process. Here is how we determined that higher tire pressures (beyond a certain point) don’t make your bike faster.
Science usually starts with a hypothesis. In 2005, the German magazine TOUR published performance tests of racing tires, and found that at 50 km/h (31 mph), the differences between racing tires were relatively small. Looking at the data, I realized that at more moderate speeds, the differences in rolling resistance could be quite significant. We designed a roll-down test. Our preliminary results showed that some tires rolled much faster than others. We refined our test protocol, and started testing dozens of tires (see BQ Vol 5 No 1 for more details and complete results).
Science also is hard work: Mark Vande Kamp rode up and down the same hill about 300 times over the course of several months, always in the early morning, when the chances of zero wind are greatest. And several times, we got up at 4 a.m., set everything up, only to have a slight wind rise despite a forecast of perfect conditions… All we could do is go back home. (And because our test track was next to a BMX practice track, we had to sweep the pavement – all 245 m of our test hill – the evening before to create a clean surface for testing.)

We also tried to find out how much performance improved with higher tire pressures. We knew that higher pressures are less comfortable, so we wanted to find out just how much speed you give up for that added comfort. To our surprise, the answer was: “None.” We found that higher pressures beyond a certain point did not make the bike roll faster. This was counter to our and almost everybody else’s expectations…  To rule out that these results were just noise in the data, we did more tests of different tires at various pressures. The results were consistent with our previous tests. Statistical analysis showed us that the results were highly significant, that means, they are unlikely just noise in the data.
Suspension Losses
The next step was to develop a hypothesis that explained what we had observed: Suspension losses are caused by friction in the the rider’s body tissues as they are vibrating. Higher pressures cause more vibrations, and hence higher suspension losses. This appears to cancel any gains at higher pressures from reduced flexing of the tire (hysteretic losses), as the tire deforms less at the contact patch as the wheel rotates.
This hypothesis also allowed us to explain why the drum test results were different – by neglecting the suspension losses, they measured only one half of the equation.
To test this hypothesis, we had to establish that suspension losses really were a significant factor, rather than some theoretical construct. (OK, the U.S. army already had established this for vibrating tank seats, but we had to show that it happens on a bicycle, too.) We did this by testing power output at constant speed on a smooth and on a very rough surface, side by side (see photo below). The differences were huge. On the rough surface (rumble strip), our rider had to put out 290 Watts more than on the smooth surface (right next to the rumble strip). That means that 290 Watts were lost through vibrations of the bike and rider’s body.

The Army studies had shown that energy absorption in human bodies was directly correlated to discomfort. After having ridden up and down our test hill 300 times, Mark wasn’t keen on riding 11 miles on rumble strips. That task instead fell upon me. I was able to confirm the Army’s results on the discomfort of absorbing hundreds of Watts as your body vibrates. Did I mention that science is hard work?
As a side effect, the suspension loss tests confirmed once again that higher pressures don’t make the bike faster even on very smooth pavement. And this time, we tested with a power meter instead of a roll-down test. So we had confirmed the results with two different methodologies. (This is much more powerful than just reproducing our initial results, which simply means running the same tests again, and finding the same results. We have done that as well, multiple times.)

After all this testing, we now can say with great certainty that increasing your tire pressure (beyond a certain point) does not make your bike faster on road surfaces that range from very rough to very smooth. In fact, on very rough road surfaces, higher pressures are a lot slower than lower pressures, because the suspension losses are so great. On most surfaces, tire pressure (beyond a certain point) simply doesn’t make a difference in speed.
Optimized Tire Pressure
Our initial tests even established at what point the performance no longer increases with higher tire pressures. For most tires and on “average” roads, this point appears to be a little higher than the 15% tire drop measured by Frank Berto. Note that the loads are given per wheel, not for the entire bike.

This means that Berto’s values are a good starting point for experimenting with tire pressures. If you want to optimize performance, you may want to go a little higher. If you are mostly concerned about comfort, you might prefer a tad lower pressure.
As always in science, there remain open questions. Is this cut-off point the same for different tires? Or do stiff tires benefit from higher pressures more than those with supple sidewalls? After all, a stiffer sidewall takes more energy to flex, so reducing that flex by all means may be helpful, even if it makes the bike vibrate more. Or is it the opposite, that stiff tires vibrate so much that running them at lower pressures is better, even if it increases the losses due to tire flex? Rest assured, we are working on this…

Continue Reading