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Tech Talk: Reports
Tech Report, with Matt Pacocha - Shimano slowly embraces carbon
Photo Gallery Below
By Matt Pacocha
VeloNews technical editor
Filed: September 11, 2007

When the Dura-Ace 7800 group was introduced for the 2004 season, it didn't feature a hint of carbon fiber despite the fact that Campagnolo was offering ample amounts of the material throughout its flagship Record group.

At the time Shimano relied on its ability to forge high quality aluminum at its Osaka factories. Four years later, carbon fiber is quite evident in Shimano's 2008 line.

Four of Dura-Ace's five wheel models feature carbon fiber rims, while a fifth uses scandium. The just released XTR Shadow rear derailleur sports a true carbon fiber pulley cage. And to put the icing on the cake, Dura-Ace will get the option of a carbon crank next year. Is Shimano abandoning its efforts to defend forged aluminum and possibly coming to the plate too late to be a player in the carbon game?

"I certainly would understand why people would think that [we're changing our tune on carbon fiber], said Devin Walton, Shimano's PR manager told VeloNews at the Eurobike trade show in Friedrichshafen. "But I think if you take a look at our history with carbon fiber, we've never actually sat down and said that we won't use carbon fiber or that we would never use carbon fiber."

Shimano may be late to the game introducing carbon into its cycling components, but the company has experience with the material that dates back to 1977. In 1981 the fishing division introduced its X-line of carbon fishing rods, the technology was cutting edge and the rods were commercially successful because of the performance they offered compared to other materials used at the time. In 1988 Shimano introduced its first cycling product that incorporated carbon fiber the SHR-100 shoe. While the use of carbon in its cycling shoe line took off, it would be seven years until the material graced another component. In 1995 the XTR M-960 E-type front derailleur mount was made from the material and in 1997 the XTR carbon v-brake booster was introduced for the following model year. In a 2001 breakthrough, the WH-7700C wheels sported a carbon rim, which developed further with in the 7701-C and ultimately the 7801-C Dura-Ace series.

Even so, 2008 will likely be remembered as the year Shimano cashed in on the wonder material, investing it throughout its XTR and Dura-Ace groups.

Over the past five years Shimano has slowly built its wheel division's clout. Through the use of it's ProTour teams and some forward thinking partnerships in both carbon and tubeless technology for mountain and road, Shimano's wheel division now competes with the best wheel manufacturing companies in the industry. Carbon has been a staple of its wheel line since the introduction of the 7801-C series in 2004.

At this year's Tour de France. Shimano-sponsored teams raced almost exclusively on the company's carbon wheels. Because of the time and miles these athletes put on Shimano's hoops this year, there have been a few changes within a product line that now includes five wheelsets. Each of them features new hubs that utilize straight pull spokes and take cues from the XTR mountain bike design.

The front hub has a stiffer 15mm aluminum axle. The two carbon tubular rims, the C50 (50mm build into a 1467 gram wheelset) and C24 (28mm front and 24mm rear build into a 1257 gram wheelset) have been slightly modified to accommodate the external spoke nipples. The 2007 rear wheel utilized a 10-speed-only aluminum freehub body spline. The new 2008 version reverts to a standard 9/10-speed spline and has 36 notched points for the pawls so that it engages at 10 degrees of movement, 125 percent quicker than the previous version.

Not quite what the pros ride - but much more convenient - are the two new carbon clinchers designed to mirror tubular wheels performance. These wheelsets utilize the same hubs and spokes, as the ProTour preferred tubular models, built onto hybrid carbon and aluminum clincher rims. The shallow WH-7850-C24-Cl wheelset weighs 1392 grams for the pair. The WH-7850-C50-CL weighs 1580 grams a set.

The big news, though, is the new Dura-Ace FC-7800C carbon crank. And it's what has some carbon naysayers up in arms. While the design relies on molded-in aluminum spider and pedal thread inserts, its arms are molded from hollow carbon. The new version is lighter and is 10 percent stiffer than the existing aluminum Dura-Ace crank.

"We didn't just jump on the first possibility for construction," said Walton. "We took our time to test and evaluate what's out there and what our engineers could bring to the plate until we found something that met our targets."

Shimano claims its weight at 709 grams with its XTR styled bottom bracket. It's set to be available next spring. Making the new crank better than its aluminum predecessor is what, Shimano says, kept a carbon model off the market until now.

"There's been a demand for the fashion of carbon fiber, at the same time there's a demand for lighter and better performing products," he said. "In this case we accommodate all of those things and that was the key for pursuing something like this."

Shimano’s new FC-7800C crank, much like the prototypes seen at this year’s Tour.

The new crank relies on a tapered spline, like XTR and a threaded BB bearing adjustment.

A cut away of the crank displaying the hollow splineless arm.

The WH-7850-C50-TU 50mm carbon tubular wheel.

The WH-7850-C24-CL 50mm carbon clincher wheel.

The rear freehub is made from titanium and now nine- and 10-speed compatible.

The WH-7850-C24-TU low profile carbon tubular wheel.

The WH-7850-C50-TU low profile carbon tubular wheel.

A close up of the low-profile clincher.

And the high profile clincher.

The tubeless compatible, scandium rimmed, WH-7850-SL wheel.