• en
  • fr
  • ja

Archive | Framebuilding supplies

My PBP Bike: The Frame

When I asked readers which part of my bike for last summer’s Paris-Brest-Paris they wanted to hear more about, the answer was: “Everything.” So we’ll make a series of short posts about the parts of the bike. I’ve already talked about the centerpull brakes here. Today, let’s look at the frame.

It’s no secret that I love my titanium Firefly. I’ve also enjoyed some great rides on carbon bikes. I wanted a very lightweight bike, and I seriously thought about getting a titanium frame or adapting a carbon U.P.P.E.R. to create a randonneur bike. In the end, I opted for steel because it’s easier to fabricate a frame that accepts all the things I need for adventures like Paris-Brest-Paris: fenders, lights, a rack, a pump… Continuer →

Continuer

Tubesets for Our Bikes: Oversized

In addition to individual Kaisei frame tubes, Rene Herse Cycles offers three complete tubesets: Superlight, ‘Mule’ and Oversize. Each tubeset is based on bikes that we have found to work extremely well. The Superlight set is the lightest steel tubeset available today, great for riders who prefer a flexible frame. The ‘Mule’ set uses an oversized down tube for a little firmer feel. It’s also better for carrying a front camping load.

The Oversize tubeset is made from thinwall oversized tubing to offer the ultimate performance for those who prefer a somewhat stiffer frame. Riders with a heavier build often have a higher power output, and they can benefit from a stiffer frame.

The oversize top tube with ultra-thin 0.7-0.4-0.7 mm walls adds stiffness to the frame without detracting from its lively feel. Kaisei keeps the ‘belly’ of the down tube to a slightly more conservative 0.5 mm, instead of the ultra-thin 0.4 mm, because the large-diameter tubes dent too easily when they are too thin. (Down tubes are larger than top tubes, making them less convex and easier to dent.) Since our tubes are available with longer ‘bellies,’ they are still lighter than other tubes with thinner-wall, but shorter, bellies.

How does a bike made with the Oversize tubeset ride? I’ve ridden a few bikes built around this tubeset, and they feel subtly different from mine. They still ‘plane’ – by most standards, this tubeset is very light and still has flex in the right places – but they do have a more planted feel. For me, they work best with a higher power output and a slightly lower cadence.

Interestingly, descending feels the same on all our bikes, regardless of the tubes used in the frame. We’ve found that frame stiffness makes little difference in how a bike handles – which makes sense when you consider that there are no significant side loads on a frame when you aren’t pedaling.

The Oversize tubeset is a great choice if you want or need a little more stiffness in your frame than our other Kaisei tubesets offer. That makes it perfect for tall, heavy and/or strong riders. This is also the tubeset I’d chose for a camping bike that carries rear panniers in addition to a front load. Above you see both my ‘Mule’ and Hahn’s Oversize bike on top of Shirabiso Pass in Japan during the Nihon Alps 600 km Super Randonnée – each bike perfect for its rider during this challenging ride.

The final tubing selection for your bike is something to discuss with your frame builder, who will design your frame based your build, riding style, preference, and intended use of the bike. All our Kaisei tubesets offer excellent performance that comes with a carefully designed balance of frame stiffness. As a Rene Herse exclusive, we offer the Kaisei tubesets in two lengths, so you can get tubes optimized for your frame size. All tubes we sell feature Kaisei’s unmatched quality and experience that comes from supplying the tubes for the frames of thousands of professional Keirin racers. We import these tubes because we feel that there are no better tubes anywhere.

Further reading:

Continuer

Myth 2: Titanium is Lighter than Steel


In part 2 of our series ’12 Myths in Cycling,’ we’ll look at why titanium isn’t always lighter than steel. I can hear you saying, “What? Everybody knows that titanium has half the density of steel.”

That much is true: The same part made from titanium will weigh half as much as the equivalent from steel. But titanium has only half the stiffness, so the part will be half as stiff. To make the parts of the same stiffness, you need to use twice as much material with titanium, and the weight will be equal. The same applies to aluminum, which is one-third as heavy and one-third as stiff. (These numbers are for the high-strength alloys; raw aluminum, titanium and iron are not strong enough to be used for cycling applications.) Continuer →

Continuer

Tubesets for our Bikes: Mule


In addition to individual Kaisei tubes, Rene Herse Cycles offers three tubesets: Superlight, ‘Mule’ and Oversize. Each tubeset is based on bikes that we have found to work extremely well. Today we’ll look at the Mule. Named after my most versatile bike, it features an unusual configuration: an oversized down tube (31.8 mm diameter) for added stiffness, and a standard-diameter top tube (25.4 mm) for the flex characteristics that give our favorite bikes their lively feel.

Originally, I built the Mule for a trip to Japan as a Rinko bike that could handle both fast randonneur rides and loaded tours. The bike was intended as a test-bed for components and parts, and it was built in a rush, so we nicknamed it ‘The Mule,’ a name used by Italian race car builders for the bare chassis that they road-tested with rudimentary bodies to finalize suspension and engines, before the car went to the carrozzeria to have its real body added.


What makes the Mule different from most bikes is that it uses an oversized down tube (31.8 mm diameter), but a standard-diameter top tube (25.4 mm). While unusual, this configuration is not without precedent: René Herse built some camping bikes, as well as some tall frames, with similar configurations. Japanese Keirin builders also build bikes with this combination of tubing diameters. And when you look at modern high-performance carbon bikes, they usually have very slender top tubes and relatively massive down tubes.

This is very different from some bikes that use an oversized top tube and a standard down tube, making both tubes the same diameter (28.6 mm). With their stiffer top tubes, these bikes don’t perform well for the BQ Team and many other riders. They also tend to shimmy, probably because both tubes have very similar resonant frequencies.


Going with a smaller top tube and larger down tube was an experiment. Would tweaking the balance of frame stiffness supercharge the Mule’s performance beyond anything we’d experienced thus far? The Mule has performed very well on many rides, but it isn’t a magic bullet: Careful back-to-back testing has shown that, for me, the Superlight tubeset gives the bike slightly better performance.


The Mule’s oversized down tube adds stiffness, yet the standard-diameter top tube keeps the flex characteristics that make for a lively feel. That makes the Mule perfect for carrying heavy front panniers. (I avoid loading up the rear, as that requires a much stiffer frame and also makes it difficult to rise out of the saddle.)


The Mule isn’t just for loaded touring. Some riders who’ve ridden the Mule really like the stiffer, more planted feel compared to the Superlight spec. The Mule doesn’t shimmy as easily – even with a Chris King headset, which is prone to shimmy, the Mule is well-behaved under most conditions.


My Mule is built with a down tube that has just 0.35 mm-thick walls. With the large diameter and super-thin walls, I have found that this tube is very easy to dent. So for the Kaisei tubes, we chose 0.5 mm walls for the unbutted center sections. We offer the tubes with longer thinwall ‘bellies,’ so the overall flex characteristics are very similar.

Even though I prefer the Superlight tubing for all-out performance, I’ve ridden the Mule in a Japanese 600 km Super Randonnée with 11,000 m (36,000 ft) of climbing, and the bike felt great throughout the ride. It was only during the back-to-back testing that I realized its (slight) performance deficit. Would I do the 765-mile Paris-Brest-Paris on the Mule, if my Superlight bike wasn’t available for some reason? Absolutely!


If I could have only one bike, I probably would choose the tubing spec of the Mule. How about you? Obviously, if you plan to go touring, the oversized down tube is a great choice. If you are concerned that the Superlight tubeset may make your frame feel too flexible, especially if you are a heavier or stronger rider, I would recommend the Mule’s tubeset as well. And if you are concerned about shimmy, the very different resonant frequencies of the top and down tubes apparently keep it from developing in most cases. Compared to the more specialized bikes in my stable, the Mule is a great all-rounder.

The final tubing selection for your bike is something to discuss with your frame builder, who will design your frame based your build, riding style, preference, and intended use of the bike. All our Kaisei tubesets offer excellent performance that comes with a carefully designed balance of frame stiffness. As a Rene Herse exclusive, we offer the Kaisei tubesets in two lengths, so you can get tubes optimized for your frame size. All tubes we sell feature Kaisei’s unmatched quality and experience that comes from supplying the tubes for the frames of thousands of professional Keirin racers. We import these tubes because we feel that there are no better tubes anywhere.
Further Reading:

Continuer

Tubesets for Our Bikes: Superlight


In addition to individual Kaisei frame tubes, Rene Herse Cycles offers three tubesets. Each tubeset is based on bikes that we have found to work extremely well. These bikes have distinct characters that I’ll describe in a series of blog posts.

The Superlight tubeset is just that – the lightest, thinnest-wall tubeset you can buy today. In the unbutted center sections (“bellies”), the tube walls measure just 0.4 mm. At the butted ends, they go up to 0.7 mm for strength at the joints. We offer the Kaisei tubes in two lengths, with “bellies” optimized for short and tall frames.

What does a bike built from the Superlight tubeset feel like on the road?


My René Herse (above) is made from tubes with these dimensions. It’s my favorite bike for spirited rides. It’s the bike that exemplifies ‘planing’ for me – a bike that gets in sync with my pedal strokes, and always seems to entice me to go faster. It’s the bike that I’ve ridden on some of my memorable rides, whether it’s ‘Charly Miller’ times in Paris-Brest-Paris (top photo) and in the Cascade 1200 brevet, or in the Raid Pyrénéen that goes non-stop from the Atlantic to the Mediterranean via 18 mountain passes (above).


In all these performances, the bike deserves a lot of credit. On long rides, it really helps to have a bike with just the right flex characteristics to synch with my pedal strokes. Pedaling becomes a subconscious routine. When we say that steel bikes can offer the same performance as modern racing bikes, it’s these bikes we are talking about.

The same characteristics make me pick the Herse for fast Saturday morning spins with the BQ Team. When we race each other up the Cascade foothills, this is the bike that I find easiest to pedal hard. It’s the fastest in these impromptu sprints because it lets me put out the most power. Compared to my other bikes, I am breathing harder at the top of the climbs, and I am more tired when I get home. And my smile is bigger, too.

The tubeset not only defines this bike’s performance, but also its feel. It always feels light, like a racehorse. Whether you like that or not depends on your taste in bikes. A very strong rider probably would find the superlight tubeset too flexible, but remember that Andy Hampsten won the 1988 Giro d’Italia on a bike made from tubes with the same dimensions. I was lucky enough to ride Hampsten’s bike once, so I can report that it feels very similar to my Herse.

While my Herse is equipped with some classic components, you could use ‘modern’ brake levers and derailleurs without changing the feel of the bike. With a different fork, you even could use disc brakes…


How about descending on a bike this ‘flexible’? Despite rumors to the contrary, it feels the same as other bikes. When you look at the physics, you realize that the bike is always balanced, no matter how hard you corner. Otherwise, it would fall over. There are no significant side loads that could flex the bike when you are coasting.

Our on-the-road experience has confirmed this: During our ground-breaking double-blind test of frame stiffness, none of us felt any differences between the bikes on the downhills – whereas on the uphills, both Mark and I were measurably faster on the two bikes with superlight tubesets.


What about the durability? You often hear the description ‘paper-thin’ for tubes this light, but when you pick up a raw tube, you realize that it’s actually quite sturdy. Most of all, the walls at the ends measure 0.7 mm – not much thinner than those of other tubes (0.8-0.9 mm). And since frames rarely break in their unbutted center sections, I am not worried about the longevity, either.

I’ve ridden my Herse for 6 years now, including the 360-mile Oregon Outback gravel race. After that ride (above), my rims had developed cracks (I use better ones now!), and my spare spokes had worn through the cloth tape I used to attach them to the fender stays, but the rest of the bike was no worse for wear.


Why not build all bikes from this tubing? First, there is the lightweight feel that some riders don’t enjoy. It really depends on your power, your riding style – these bikes work best with a light touch on the handlebars – and your preferences. Furthermore, with a tubeset this light, these bikes are more prone to shimmy. It hasn’t been an issue on my Herse, but that bike uses a needle bearing headset that dampens the steering slightly. Also, I wouldn’t recommend this tubeset on a bike that commonly carries a heavy load. The Herse is fine with a heavily loaded handlebar bag, but if I were to ride a lot with loaded front low-riders, I’d pick a stiffer down tube.


One last datapoint is that I am 181 cm tall (5’11”) and weigh 70 kg (154 lb). I ride a relatively large frame (58 cm seat tube, 57 cm top tube, c-c). Shorter tubes are inherently stiffer, so I feel that this tubeset makes even more sense for smaller frames. On the other hand, taller or significantly heavier riders may need a stiffer tubeset. Fortunately, we offer those as well.

The final tubing selection for your bike is something to discuss with your frame builder, who will design your frame based your build, riding style, preference, and intended use of the bike. All our Kaisei tubesets offer excellent performance that comes with a carefully designed balance of frame stiffness. As a Compass exclusive, we offer the Kaisei tubesets in two lengths, so you can get tubes optimized for your frame size. All tubes we sell feature Kaisei’s unmatched quality and experience that comes from supplying the tubes for the frames of thousands of professional Keirin racers. We import these tubes because we feel that there are no better tubes anywhere.
Further Reading:

Continuer