Geoff Kabush (Maxxis-Rocky Mountain) is racing this season on a prototype carbon 'cross chassis.
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Team-only chassis and custom tubulars for the Canadian Olympian
Geoff Kabush (Maxxis-Rocky Mountain) arrived at last Saturday and Sunday's UCI races in Boulder, Colorado with a new carbon fiber 'cross chassis currently unlisted in the Rocky Mountain catalog. According to team head mechanic Gary Wolff, Rocky Mountain supplied a few of these frames just for Kabush and might turn them into a production item but for now, they're team-issue only.
Kabush's frame features most of the features common to modern 'cross chassis these days: a tapered front end, internal cable routing, and what look to be carbon rear dropouts. We don't have a frame or fork weight available – and Wolff didn't know it – but total weight on Kabush's complete bike is a very competitive 7.55kg (16.64lb).
Easton adds even more carbon fiber to the mix with sub-1,200g EC90 SLX tubular wheels, the EC90 seatpost with molded carbon shaft and clamp, and the semi-anatomic EC90 SLX handlebar, and even TRP gets into the composite mix with its CR950 cantilevers.
TRP have released a slightly wider-profile CR959 SL cantilever to better match the power of Avid's Shorty Ultimate lever but Geoff Kabush sticks with the original CR950
Shimano provides a complete Dura-Ace drivetrain and mechanical transmission, including the shift/brake levers, both derailleurs, the chain, 12-27T cassette, and forged aluminum crankset with 'cross-specific 39/46T chainrings. As is common practice, Kabush runs the levers run up on the bars and despite his large-sized hands, the reach is brought in just a touch for easier braking and shifting while in the drops.
Kabush is sponsored by Maxxis but the company notably doesn't make 'cross tubulars and at this level of the sport, they're a virtual necessity to even think about being competitive. The team has gotten around the problem, however, by sending stock Maxxis clincher tires over to tubular tire expert Dugast, where the treads are carefully removed and them hand-glued on to a supple 32mm-wide cotton casing.
Kabush races on custom Dugast tubulars covered in Maxxis treads. He uses the Raze for most days
The end result is the tread that Kabush wants but also with the suppleness he needs. For most courses, Kabush says he runs the Maxxis Raze tread with its fast-rolling but reasonably openly spaced square knobs but he also has a set of custom Mud Wrestler tubulars for sloppier courses.
Rounding out the mix are fi'zi:k Antares k:ium saddle and padded tape, an FSA integrated headset, Crankbrothers' feathery Eggbeater 11 pedals, and Shimano cables, housing, and sealed end caps.
Kabush uses an alloy stem but a carbon bar on his Rocky Mountain carbon fiber 'cross bike
This article originally appeared on BikeRadar
Complete bike specifications
Frame: Rocky Mountain Solo Carbon prototype
Fork: Rocky Mountain Solo Carbon prototype
Headset: FSA Orbit integrated
Stem: Easton EA90, 120mm x 0°
Handlebars: Easton EC90 SLX3, 44cm (c-c)
Tape/grips: fi'zi:k dual:tape
Front brake: TRP CR950 w/Easton carbon-specific pads by SwissStop
Rear brake: TRP CR950 w/Easton carbon-specific pads by SwissStop
Brake levers: Shimano Dura-Ace STI Dual Control ST-7900
Front derailleur: Shimano Dura-Ace FD-7900
Rear derailleur: Shimano Dura-Ace RD-7900-SS
Shift levers: Shimano Dura-Ace STI Dual Control ST-7900
Cassette: Shimano Dura-Ace CS-7900, 12-27T
Chain: Shimano Dura-Ace CN-7900
Crankset: Shimano Dura-Ace FC-7900, 175mm, 39/46T
Bottom bracket: Shimano Dura-Ace BB-SM7900
Pedals: Crankbrothers Eggbeater 11
Wheelset: Easton EC90 SLX tubular
Front tire: Custom Maxxis Raze tread on Dugast tubular casing, 32mm
Rear tire: Custom Maxxis Raze tread on Dugast tubular casing, 32mm
Saddle: fi'zi:k Antares k:ium
Seat post: Easton EC90 Setback
Bottle cages: n/a
Other accessories: Shimano SP41 derailleur housing and sealed end caps
Rider's height: 1.90m (6' 2")
Rider's weight: 75kg (165lb)
Saddle height, from BB (c-t): 775mm
Saddle setback: 75mm
Seat tube length, c-t: 585mm
Seat tube length, c-c: 540mm
Tip of saddle nose to C of bars (next to stem): 570mm
Saddle-to-bar drop (vertical): 50mm
Head tube length: 180mm
Top tube length: 570mm
Total bicycle weight: 7.55kg (16.64lb)
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