In June 2010, the Union Cycliste Internationale approved the use of disc brakes on cyclo-cross bikes. It's widely believed that the world governing body for cycle sport came to its decision following representations from Shimano. Since that surprise announcement from the UCI it was expected that brake manufacturers, large and small, would start to develop disc brakes for road bikes.
The first to market is likely to be Formula of Italy, which has working prototypes on its booth at Taipei Cycle. The discs are fitted to a beefed-up Colnago C59. Close by in Hall 1, Colnago has the same disc-equipped bike on its booth. (The bike features Shimano’s Di2 electronic shifting but the hydraulic road-bike dual-paddle brake levers plugged into the Di2 wiring are by Formula).
SRAM and Shimano also have road disc brakes in the works, although not for public display at the show.
Brake makers would like the UCI to ratify use of disc brakes on road bikes. Such brakes, common on mountain bikes for the best part of a decade, are more powerful than caliper brakes and work better in the wet, too. Concerns about heat dissipation and disc-brake activated wheel ejections when using quick release skewers have been addressed, brake manufacturers told BikeBiz.
High-quality QRs are likely to be able to withstand high ejection forces on vertical drop-outs but fitting thru-axles to road bikes is an even safer option, although speed of wheel changes during race conditions would a factor militating against thru-axles. However, for sportive and general road use, there's little reason to fit quick release skewers and consumer bikes fitted with road discs may dispense with QRs.
To fit disc brakes on road bikes, bike manufacturers will have to design new, beefier frames; road disc brakes will not be available for the after market in the short term. Disc brake systems will likely remain heavier than caliper systems for a time.
Despite weight penalties, brake manufacturers believe there are clear performance and safety benefits of disc brakes. The performance benefits come from the ability to descend faster thanks to better braking capabilities.
Road bike purists are already claiming that disc brakes make road bikes look too much like mountain bikes, and they have stated they prefer the classic lines of bicycles equipped with traditional brakes. However, many professional riders will welcome better braking performance, especially on dangerous descents and use of disc brakes by pros will create demand.
Charles Becker, category manager for road and triathlon at SRAM, said:
"We'll be supplying road discs for testing by the UCI soon. Regardless of what the UCI decide we'll be producing the kit for the market. For us it's a safety issue as well as a performance issue. Yes, there are compatibility issues for team and neutral support at pro races but that's not an insurmountable problem. I think the UCI will see sense on this one."
That's also the view of Giancarlo Vezzoli, the engineer in charge of the road disc project at Formula.
"You may be surprised at how quick the UCI makes the right decision. All the brake manufacturers are united. The UCI will see this is a safety decision, nothing to do with politics."
Formula's road discs were created for Colnago (pic above shows Ernesto Colnago with the disc-equipped C59) but will be available to any OE customer.
Vezzoli (pictured above) said the 160mm front and 140mm rear rotors - and the hydraulically activated aluminum paddle levers - had been tested extensively.
"We did 20 minute mountain descents using just the front brake or just the back brake, locked on all the time, and everything was fine."
Colnago is the first to make a commercially-available disc brake equipped road bike (Canyon produced a concept bike in 2006; the bike never made it to production, because of the problems with equipping road bikes with discs, as stated on the link) but other manufacturers are not far behind. Specialized is rumored to have a disc brake road bike ready to roll. Not all manufacturers are convinced. Cervélo's Phil White has claimed road discs can heat up and fade on long descents, or fail completely.
Manufacturers discussed road discs - and other tech matters - at a members-only meeting held oin the morning of the last trade day of the Taipei show; a meeting organised by the World Federation of Sporting Goods Industry, which represents bicycle manufacturers in technical discussions with the UCI. Robbert de Koch, secretary general of the World Federation of Sporting Goods Industry, (pictured at the TaiSPO sporting goods show, run at the same time as Taipei Cycle) told BikeBiz that the UCI has yet to receive any road disc brakes to test but once it has done so a decision will be made on whether or not to allow the use of road discs in professional road races.
A version of this article appeared first in the Taipei Show Daily.