Author Archive | Jan Heine

Even in these troubled times, most of us continue to ride our bikes, at least here in North America. We’ve been encouraged that even during the ‘shelter-in-place’ in the San Francisco Bay Area, solo bike rides continue to be permitted.

Over the last year, we’ve worked on re-introducing FMB tubulars to the North American market. FMB tubulars perfectly complement to our Rene Herse clinchers. They feature similar no-nonsense tread patterns for road, dirt and mud. FMB’s three casings all offer supple performance, but they vary in their degrees of sidewall protection. Continue Reading →

Many of you asked for more tires with Endurance casings… The 700C x 35 has long been a favorite of gravel racers and all-road riders. Now you can choose between the versatile Standard casing, the superfast Extralight and the tough (but still lightning-fast) Endurance. Continue Reading →

As it can happen with new products, the demand for our Endurance casings has outpaced the supply recently, and some popular models have been out of stock. We’ve stepped up production, and now all tire models are back in our warehouse, ready to ship. That includes the 700C x 38 mm Barlow Pass, a favorite of gravel racers… Continue Reading →

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.

Rene Herse tires are available in many widths, with two tread patterns and four casings. All this so you can find tires that are ideally suited to how and where you ride. Today, let’s look at the different casings. Which is best for you? Continue Reading →

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?

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:

• Why a herringbone tread provides more traction.
• More information about Rene Herse tires.

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!

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:

• Click here to read the full Gran Fondo article.

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:

• Rene Herse tires and Panaracer sealant
• Tips for setting up tires tubeless
• Why tubeless tires aren’t faster than tubes

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).

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).

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.
 

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).

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!