Quick-Step’s German sprinter Marcel Kittel became the first rider to win a stage of the Tour de France on a bike equipped with disc brakes earlier in the week and now he's added a second. Here’s the Specialized S-Works Venge ViAS Disc in question.
The Venge is Specialized’s aero road bike, hence features like a deep section down tube that’s cutaway around the rear of the front wheel, a seat tube that’s cutaway around the leading edge of the rear wheel, an aero seatpost and a fork crown that’s integrated into the frame.
It might seem odd to stick disc brakes on an aero road bike because there’s a slight penalty to be paid in terms of drag, but Specialized claims the disadvantage is tiny – less than 4secs over 40km at 40km/h, rising to 8secs at higher yaw (apparent wind) angles.
Marcel Kittel seems sold on the benefits of discs having taken his first win on the S-Works Venge ViAS Disc in the Dubai Tour back in January. Perhaps there’s some encouragement from the team sponsor to embrace the technology – who knows? – but you can’t argue with a Tour de France stage win (and, we’re guessing, more to come).
The paintjob is the same as Kittel has on his rim brake Specialized S-Works Venge ViAS with a colourful S-Works logo. The design is carried over onto the top tube, seatstays and the S-Works Romin Evo saddle.
Specialized’s Ron Jones said, “I spent some time researching [explosive speed] and came across the CERN particle accelerator and some of the experiments performed there. They shoot electrons towards each other at the speed of light and record the impacts which create these awesome explosive graphics.”
Kittel’s bike is fitted with Shimano’s top-level Dura-Ace Di2 groupset, and that includes the disc brakes. Shimano has only recently added disc brakes to the Dura-Ace groupset for the first time. Previously, you could get Dura-Ace compatible disc brakes but they weren’t actually part of the group. Shimano says that the current road bike disc brakes out there are essentially repurposed mountain bike brakes whereas the new Dura-Ace design is its first real road bike disc brake with 360g shifters and 515g brakes.
It’ll be interesting to see how many stages Kittel rides with discs. There was certainly no danger of them overheating on the wet stage from Dusseldorf to Liege and Shimano’s engineers have worked hard to ensure that remains the case when descending hot mountain passes in the height of summer, new rotors having been designed to dissipate heat better than the brand’s existing Ice Tech Freeza rotors. A one-piece alloy body extends right from the edges of the rotor to the centre and there’s a whole lot of surface area from which heat can escape.
The R9170 dual control levers are almost the same shape as the R9100s (for mechanical shifting and cable operated rim brakes) and the R9150s (for Di2 shifting and cable-operated rim brakes). The only real difference is that the R9170 design is a bit more of a handful where the hydraulic hose exits at the upper inner edge.
As well as making the design aesthetically more attractive, the idea is that a rider like Kittel can switch from a rim brake bike to a disc brake bike without noticing much of a difference ergonomically.
Kittel uses 175mm cranks and a dual sided crank-based Precision Pro power meter from 4iiii.
Those are 9000 Series Dura-Ace pedals on Kittel’s bike rather than the new 9100 ones. We saw quite a lot of other riders using these still.
The wheels are Roval CLX 50s, the 50 referring to the rim depth in millimetres, and the tyres are Specialized’s S-Works Turbo Gripton in a 26mm width.
The single piece handlebar/stem is the Metron 5D from Vision which is designed with aerodynamics in mind.
Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.