Pro bike: Rohan Dennis's Hour Record-winning BMC TrackMachine TR01
BMC’s young Australian time trial talent Rohan Dennis was widely quoted ‘shooting his mouth off’ about his ability to beat Jens Voigt, after hearing that the German would be attacking the hour record in September 2014. His words, whether calculated or not, brought him to the Velodrome Suisse, literally yards from sponsor BMC’s factory, and ironically the scene of Voigt’s successful ride.
Rohan dennis in full flight on his way to breaking the hour record:
Dennis on his way to the record
Beneath a giant poster of the famous German, Dennis successfully attacked Matthias Brandle’s current record of 51.852km on Sunday 8 February setting a new mark of 52.491km, subject to UCI ratification. Whilst Grenchen was smothered in a covering of wind-driven snow, the track’s heating had been turned up for days to maintain the sort of air temperature necessary to assist with a record attempt.
In the relatively short time since announcing his attempt, the BMC Racing Team and BMC’s recently named Impec Advanced R&D Lab have been working together to create the perfect bike for the ride. Fortunately, BMC already makes the Trackmachine TR01, which was principally designed for the Swiss national track team and easily changeable from pursuit duty to omnium or sprint spec to reduce the team’s travelling inventory. Key to this adaptability is a clever modular aluminium stem that adjusts for angle with a single bolt, and accepts up to 30mm of almost invisible spacers for additional reach.
BMC’s impec advanced r&d lab took 3t’s brezza nano track bar and integrated it with an adapted stem and the hinge fork and wrapped it all in carbon to add strength:
The R&D team used the stem’s mounting bolt as the basis for Dennis’ machine, and added a 30cm-wide 3T Brezza II Nano LTD track bar with time trial extensions, then blended them both together and integrated the structure and the hinge fork with wraps of structural carbon fibre. The resulting setup adds rigidity, especially since the risers for the extension bars are also integrated in to the design. There’s some weight savings too compared with separate components, and of course the shaping conforms to the UCI’s 3:1 regulation.
As a rider who has competed at the highest level on both road and track, Dennis is well used to switching between track and road drivetrains. His early specific training used a conventional track setup, but the desire to gain additional data to assist with preparation, and during the attempt itself, meant a switch to a 175mm Shimano Dura-Ace 9000 SRM road crank with a 56-tooth road chainring and normal road chain.
Alongside a normal shimano dura-ace track sprocket, the 6mm added width of bmc’s custom version is clear:
A custom machined rear cog compared to a standard Dura-Ace model
This in turn produced a chainline that was more widely spaced than a track setup, and therefore not aligned with the sprocket. To correct this, BMC’s R&D Lab machined several 13 and 14 tooth sprockets from solid blocks of alloy, which positioned the sprocket 6mm further outboard than usual, and have recesses for the lock ring.
Disc wheels are standard equipment for modern hour record attempts, and Dennis has a pair of unbranded glossy black discs that are very light, and shod with Continental Olympic 19mm tubulars that were inflated to a pressure between 14 and 15 bar. There is no official information regarding the precise wheel specification, but anyone who’s followed recent hour record rides may be able to draw their own conclusions.
Rohan’s usual team issue fizik arione r3 braided saddle with the srm head unit fixed in place:
SRM head unit attached to the seatpost
Dennis chose to ride his usual team issue Fizik Arione R3 braided saddle, mounted to the TR01’s standard carbon track seatpost. This one though has been customised with a 3D printed mount for the SRM head unit, since record rules dictate that the rider may not have any form of device mounted within their sight.
But Rohan Dennis certainly had the clock in his sight on Sunday. And now, after his ride of 52.491km, he is the first Australian holder and joint-youngest record holder in the modern era.