Racing is back on and the only thing more intense than the tightly packed calendar is the competitiveness of the racing itself. While the rain held off for the men's World Championship race, the previous week of rain had made the Leogang track greasy and challenging. Sarrou was victorious, overcoming the challenging course to take the rainbow jersey and break Nino Schurter's five-year winning streak. The BMC Fourstroke platform also helped fellow Frenchmen and Absolute Absalon-BMC teammate Titoan Carod into third spot.
Sarrou controlled the race from start to finish; ‘I had such an amazing day on the bike, like very rarely in my career so far. I had amazing sensations, from the start actually. I didn’t attack, just raced my own pace and could focus on riding clean. I didn’t allow myself to think about what was happening until I had the finish line in sight.’
To celebrate Sarrou's rainbow jersey win, BMC created a special Fourstroke bike for him to ride at the following European Championships. Sarrou took his golden Fourstroke, featuring the same spec as his World Championship winning bike, to take 5th place.
BMC's Fourstroke has been on the progressive geometry end of the XC race world for a few years, choosing a longer reach and slacker head angle to give increased stability and control in technical or difficult conditions. Sarrou reflected on the bike after his World Championship success; ‘It is the best bike at the moment. The aggressive geometry and the front angle especially made me feel super stable on the steep and technical downhills. Climbing and getting back up to speed after corners was also very easy. The Autodrop might be seen as a “little detail” but it makes a huge difference. It allowed me to push further out of the saddle before a downhill and save energy without having to push the saddle down.’
Beyond the geometry and eye-catching paintwork of Sarrou's Fourstroke, the most interesting feature is BMC's Autodrop seatpost. Dropper posts have started to be utilized more in XCO races, as descents become increasingly technical the advantages gained by dropping the seat out the way offsets the weight penalty.
Many of BMC's bikes feature a neatly integrated dropper system however BMC's Impec Lab has gone further to develop the Autodrop seatpost which uses compressed air to drop the saddle rather than the rider having to apply force by sitting on it. This can offer a huge advantage, limiting the rider's input and allowing them to focus on the terrain and pedaling without interruption.
BMC claims that the Autodrop system, which was first tested at the 2019 Lenzerheide World Cup, has a capacity for 90 actuations before reverting to a standard dropper post function. BMC hasn't released any details on stroke length or weight but we can speculate that the system must be competitive if it's being used at World Champs. We don't think we are the only ones excited by this innovation and BMC has hinted that now the system is race-proven they may consider making Airdrop commercially available in the future.
Beyond the dropper tech, Sarrou's bike is unusual as suspension duties are not handled by Rockshox or Fox, the French rider is supported by Suntour and uses a Suntour Axon Werx 34 fork and Suntour Edge RL-R. The fork has 100mm of travel and beefy 34mm uppers to assure stiffness and steering precision to complement the Fourstroke capability to descend.
Drive is handled by SRAM XX1 Eagle AXS electric 12sp drivetrain which drives the front and rear-specific Duke Lucky Jack SLS2 6Ters hookless wheelset. For the drier European Championship course, Sarrou opted for Vittoria Mezcal 29x2.25 tires.
|Fourstroke Frame, size L
|Suntour Axon Werx 34 100 mm, 90 PSI, 6 air volume spacer
|Suntour Edge RL-R, 120 PSI
|BMC carbon 720mm
|Togia Undercover Stratum
|Lizard Skin DSD 32.3mm
|Sram XX1 Eagle AXS
|SRAM XX1 Eagle AXS
|Sram XX1 Eagle DUB SL 175mm, plateau 36T
|SRAM XX1 Eagle
|SRAM XG-1299 Eagle
|Sram Level Ultimate
|Duke Lucky Jack SLS2 6Ters
|Vittoria Mezcal 29x2.25
|Time Atac XC12