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Tour Tech Talk: It ain’t a toolbag; Oddball rings

Tool bag?Dear Lennard,The other day during stage 9 I noticed a small black box under the saddle on Jens Voigt's Cervelo. Obviously he wasn't carrying a tool kit like us mortals, so what was it? A radio?Brett Dear Brett,I am posting this since I continue to get this question every day, even though I answered it already. For the answer, check out this link. You really ought to check out the daily SRM telemetry, especially in the Pyrenees and the final time trial. There are a lot of riders hooked up with them. The display isonly live during the stage and there is no file to see

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By Lennard Zinn

Whuttup with Bobby and those rings?

Whuttup with Bobby and those rings?

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Tool bag?
Dear Lennard,
The other day during stage 9 I noticed a small black box under the saddle on Jens Voigt’s Cervelo. Obviously he wasn’t carrying a tool kit like us mortals, so what was it? A radio?
Brett

Dear Brett,
I am posting this since I continue to get this question every day, even though I answered it already. For the answer, check out this link. You really ought to check out the daily SRM telemetry, especially in the Pyrenees and the final time trial. There are a lot of riders hooked up with them. The display isonly live during the stage and there is no file to see afterward. Go straight to this link or this one, which only has the Lampre riders, but today only Salvatore Commesso was on the live power telemetry anyway.
Lennard

Bobby J’s rings?
Dear Lennard,
What is the deal with Bobby Julich’s chain rings? They talk like it is the next great thing. How is it different that the Bio-Space Shimano rings that were out in the late 80’s, which no one really stuck with.

Dan Casebeer (bike shop owner in Minneapolis) says it is for peoplethat only want to push down. Why would a pro use them, or anyone?
Gerald

Dear Gerald,
They are called Osymetricchainrings, and I spoke with the inventor, Jean-Louis Talo, at the Tour start in Fromentine. Bobby Julich certainly believes in these odd-shaped chainrings, as, of course, does Talo. Alexandre Vinokourov won a bronze medal in the world’s TT last year, and Julich got the bronze in the Olympic time trial with them.

Cañada takes a similar approach

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They are very different from Biopace, since Biopace gave you a smaller gear on the downstroke and upstroke, and a bigger gear at the top and bottom. Osymetric chainrings instead give you a higher gear when you are pushing down and pulling up, and a lower gear when passing over the top and bottom of the stroke.

Talo is careful to repeatedly point out that this is a very complicated, mathematical curve; it is not an oval, which he claims would be less efficient (even!) than round chainrings. He claims that his chainrings are one mph faster uphill and 0.6mph faster on the flats than round chainrings, and that even top downhillers whom I am not at liberty to disclose are winning on them.

On the subject of odd-shaped chainrings, Saunier Duval’s David Cañada is also using non-round chainrings. These are not Osymetric, and they are on a Campy crank (135mm bolt circle diameter), whereas the only Osymetrics I have seen were for the 130mm bolt circle diameter of Shimano. I’m sure Jean-Louis Talo would cringe, protesting that the curves are completely different, but they appear to have a similar intent to Osymetric – somewhat oval chainrings that give the rider a higher gear on the up- and downstrokes and a lower gear at the top and bottom

Also, on the subject of different strokes for different folks, Liquigas’s Stefano Garzelli has Power Cranks on his training bike. Those are the units with the one-way clutch in each arm, which triathletes in general have been more willing to try in the past than roadies. The only way that Power Cranks stay at 180 degrees to each other is if your legs keep them that way; each crankarm does not come up to the top of the stroke unless you pull it up. The weight of the foot, which most riders leave on the pedal at the bottom of the stroke, holds the crank down. When coasting, both pedals will be at the bottom unless the rider holds one leg up the entire time.

There is no question that Power Cranks improve a rider’s upstroke. I have ridden with them quite a bit and am not eager to use them again, but that is not because I don’t think they would improve my pedaling. It’s just that I only ride for fun any more, and I find the ride less fun when I have to constantly work, even when coasting. If I were still racing,I would probably want to have a bike set up with them.

The use of these cranks, chainrings, and telemetric power-measuring systems by top riders is another sign of the influence that Armstrong’s Tour domination with his calculated, scientific approach is having on the peloton. Coaches and teams now try new things looking for an edge, rather than sticking to the old-school traditions from the days of Eddy Merckx, as they were far more prone to do ten years ago. Now you find a strangeAmerican product, the Power Crank system, on Garzelli’s bike, and strange chainrings on the bikes of other top riders, something that old-school coaches, who would have been listened to not long ago, would resist.
Lennard

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