Lots of buzz has surrounded the UCI's decision to allow disc brakes on cyclo-cross bikes and the performance potential is certainly there: superb mud clearance, more consistent braking in poor weather and reduced maintenance. The reality of available high-end gear is still a year or two away, but there were some tantalizing stopgap bits on display at this year's Eurobike show along with some forward-thinking framesets.
Mechanical-to-hydraulic converters from TRP, Hope and Tr!ckstuff
TRP, Hope and Tr!ckstuff each displayed their own take on the mechanical-to-hydraulic converter box designed to work with currently available road brake levers. While the execution varies slightly, the concept behind all of them is nearly identical: the input cable is clamped to a short arm that then actuates a hydraulic master cylinder piston, which is in turn connected in a sealed system to a hydraulic disc brake caliper.
Hope's solution differs slightly in that the cable is directly attached inline with the piston. This means there's no mechanical advantage built into the system but the upside is a cleaner-looking final product that also looks like it might be lighter than the other two (Hope didn't have claimed weights available).
TRP say their Parabox mechanical-to-hydraulic converter will be shipping to dealers this month
These interim solutions aren't as clean-looking or – at least in theory – powerful as a full hydraulic setup but all things considered, the drawbacks are fairly minimal for early adopters who want to go with discs right now. The steel cable run is very short, the units' placement below the stem is generally out of the way and well protected, and predicted weight penalties are modest at about 250g in total relative to a standard cantilever setup.
Jumping on to the disc-equipped 'cross bandwagon will cost you, though. TRP's complete Parabox setup with calipers and rotors is US$459.99 while the Hope is similarly priced at £300. Hope's master cylinder adapter won't be available until November or December but the TRP unit should be in stores later this month.
The Tr!ckstuff Doppelmoppel is similar to the TRP Parabox but the actuator arms are turned sideways and the overall layout is switched front to back
Look debut disc-only X-85 carbon 'cross frame
Sitting quietly amid the scrum of Look's Eurobike booth was their new X-85 carbon 'cross frame, built with tube-to-tube construction, dedicated 'disc brake fittings front and rear, and no provision for rim brakes. The aesthetics were clean and mud clearance was generous, with no hardware running close to the rims and no bridges joining the rear stays – arguably the biggest potential advantage of running discs in 'cross.
Look claim a medium X-85 frame weighs a competitive 1,150g, with the matching carbon fork adding another 550g. So-called 'FLEX' seat- and chainstays with strategic shaping through their length promise a smooth ride quality along with the relatively small-diameter 27.2mm seatpost. Rear dropout spacing is set at 135mm to better accommodate the generous availability of mountain bike disc hubs and 29er disc wheels.
Look quietly showed off their new X-85 disc-only 'cross bike at this year's Eurobike show. Interested buyers won't be able to get one until the spring, however
While the concept of the X-85 is cutting-edge, a couple of other aspects of the frame are rather traditional, including the threaded bottom bracket and straight 1-1/8in head tube – though with the brake located down by the dropouts, there's less of a need for a stiffer tapered head tube to combat brake shudder. Look will offer the X-85 in four sizes for around US$3,499-3,699 but you won't be able to get one until next spring.
Stevens show off Niels Albert prototype disc cyclo-cross rig
German bicycle powerhouse Stevens displayed their own carbon disc-equipped 'crosser, though unlike the Look it was still officially deemed a prototype. Nonetheless, it looked ready for production with its tidy post mount carbon disc tabs front and rear, ample clearances throughout, internal cable routing, and even an integrated seatmast that's guaranteed not to slip after a remount.
One of the most striking 'cross bikes on display at this year's Eurobike show was this prototype disc-only Stevens
According to Volker Dohrmann of Stevens, the hesitance of many pro racers to try discs is due more to tradition and habit than any performance shortcoming. He points out that "wheel changing is very fast and easy on a 'cross bike with disc wheels", owing to the fact that there are no brake arms to open up.
However, Dohrmann says the major barrier to widespread acceptance in the upper ranks of the sport is the lack of any properly integrated hydraulic system that can fully take advantage of the potential all-weather performance and minimal weight penalty.
You can find out more about the Stevens prototype in the video below:
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Stevens will only offer an alloy 'cross disc bike for now but when the supporting components are finally completed, the company will clearly be ready to pull the trigger. "Within the next year," said Dorhmann, "I predict we'll have the combination of Shimano [Dura-Ace] Di2 drivetrains and hydraulic disc brakes which could also be a good way for road bikes, not just for cyclo-cross."
Dedacciai unveil a disc 'crosser of their own
Most riders don't think of Dedacciai as a frame company but the Italian outfit actually offer 10 models for 2012, including six carbon road frames, a titanium road frame, a time trial chassis, a 29er hardtail (!) and one carbon 'cross platform that's intriguingly disc-only.
Dedacciai's lone 'cross frameset is boldly disc-only for 2012
The new Super Cross boasts a 1,050g modular monocoque frame with a press-fit bottom bracket, a huge asymmetrical down tube and seat tube, tapered 1-1/8 to 1-1/2in head tube and slim seatstays. Aluminum post mount disc tabs are featured at both ends and clearances through the stays and fork crown are impressive, with no shelf behind the bottom bracket on which mud can accumulate, either.
The matching carbon fork is light, too, at a claimed 420g – lighter than ENVE Composites' offering, in fact. Routing for the derailleur lines is partially internal – running through the top tube but exiting out around the seat cluster – but the rear brake is externally run with zip-tie mounts for either a hydraulic line or full-length housing.
Plenty of other companies were showing off disc brake solutions for cyclo-cross bikes at this year's show. Check out our image gallery for more details