CHICAGO, IL (BRAIN) Feb 1, 14:50 MT—Almost overlooked in SRAM's press release announcing its new Red group Wednesday were a few sentences about the company's plans to bring hydraulic disc brakes to the road and cyclocross market.
It's been rumored that SRAM is developing RED level road hydraulic brakes. We want to confirm this and let you know that we are currently working on a hydraulic disc brake and a hydraulic rim brake. Information on pricing will come at a later date and no photos are currently available.
• Hydraulic disc brake: RED level / Drop bar DoubleTap lever actuated / All new master cylinder and caliper / 140-160mm discs
• Hydraulic rim brake: RED level / Drop bar DoubleTap lever actuated / tire clearance up to 28C / Firecrest rim compatible
Commercial availability - Fall 2012
Custom builders have been experimenting with disc brakes on drop-bar road bikes at least since Avid introduced its cable-pull BB7 disc calipers nearly 11 years ago. A few larger suppliers, including Redline, also have offered moderately priced production road and cyclocross bikes with discs.
The push for discs on higher-end production bikes has been building steadily over the last three years. The growth of cyclocross in the U.S. has contributed to it, as many roadies and mountain bikers trying 'cross for the first time were disappointed with the performance of traditional cyclocross cantilever brakes.
The movement got another boost when the UCI legalized discs in international cyclocross competition in late 2010. And the same year, Volagi showed a polished, high-end carbon production road bike with (cable-pulled) discs at Interbike. With its hidden cable routing the Volagi gave many their first vision of what a disc-brake road bike might really look like.
Another factor has contributed to the road-disc movement: carbon rims. Wheel makers have struggled to make effective, durable braking surfaces on carbon rims, which has held back their use, especially for clinchers. disc brakes would nicely eliminate that problem.
A variety of options have developed to address the demand. Adaptors like one from TRP allow the use of road shifter/brake levers with hydraulic brakes. Several companies are working on hydraulic road brake levers that would integrate with Shimano's Di2 shifter buttons. And Campagnolo and Shimano are rumored to be developing their own such levers.
Magura has a new hydraulic rim brake for time trial bike use, and SRAM's hydraulic rim brake is likely destined for the same use.
But SRAM's announcement Wednesday marks the first official acknowledgment from one of the major component makers that they are moving forward with hydraulic road discs.
SRAM's significant OE business means a variety of supporting manufacturers are probably already hard at work solving some of the challenges that road disc brakes present.
Among those challenges is designing a quality carbon road fork for discs. Such forks need to be re-engineered for the disc brake stresses and need forward-facing dropouts to prevent braking torque from pulling the wheel out of the fork. Specialized and Spot Brand, among others, already have developed carbon disc 700c forks for cyclocross use. Expect to see many more options soon.
On the other end of the bike, the industry needs to settle on the proper rear axle width. Many engineers are calling for road bikes to adopt the mountain bike standard of 135mm OLD to make room for the disc and as many as 11 cogs. It also would allow the use of 29er hubs and wheels that are already on the market.
Chain- and seatstays also will need to be engineered to account for the different stresses of a disc brake.
Brakes themselves will need to get lighter, while their power and modulation will need to be optimized for road use. Quick wheel replacement and the elimination of any disc rub will be more important in the road market. A little rotor rub is hardly noticeable offroad, but would infuriate some road riders on a long solo jaunt.
The UCI has not yet allowed disc brakes in international road competition, and a certain type of roadie, even those without a dream of racing internationally, will decline to adopt disc brakes until he sees his Tour de France heroes using them. (Our use of the masculine pronoun was intentional: Volagi's Robert Choi says he's found little such resistance among women.)
But discs in competition would be problematic. They would add yet another type of wheel that neutral support vehicles would have to stock; if the industry doesn't settle on a standard rear axle width and disc diameter, even more wheels would have to be available. And it could be difficult to prevent damage to rotors when wheels and bikes are being shipped between events and carried in or on race vehicles.