Tour de France 2025 - Stage 6: Bayeux - Vire Normandie | 201.5 kilometres | 3550 vertical metres
The second longest stage has a profile that could play into the hands of a breakaway group: 3550 metres in altitude have to be overcome. Five climbs belong to the third category, with the first one inviting a breakaway after just 35.5 kilometres. In the finale, there is a fourth category climb to master, the Côte de Vaudry (1.2 kilometres, 7.2%). In the middle section, the Côte is up to 11 per cent steep and flattens out towards the top. From there, it is another 4.4 kilometres to the finish. The 700 metre long final ramp has an average gradient of 10.2 per cent, but reaches 14 per cent before the finish.
A bunch sprint is out of the question. Either an escape group will get through or there will be a showdown of a reduced peloton with attacks on the last two climbs. A classification rider could also try to gain a few seconds.
From a material point of view, the stage is tricky. For a long escape, an aerodynamically optimised bike is best, that much is clear, and this is largely independent of how many spikes there are in the wavy profile. We know this from the numerous calculations of recent years. Calculated over a longer distance, aerodynamics always wins, and then we are talking about minutes in a direct comparison between aerodynamically optimised wheels and those that do not exploit the potential.
A late decision for the stage win, for example with a sprint on the final climb, is more difficult to predict from an equipment point of view. With a 14% gradient just before the finish, experience shows that the slightly lighter bike will prevail.
If it is unclear how the finale will unfold, a bike that combines minimal weight with maximum aerodynamics is the best choice, as the rider is always optimally equipped. This would be the case, for example, if the attack was launched on the penultimate climb and the rider had to defend the lead right up to the final climb.
Reweighed
Our colleagues on site at the Tour de France were able to reweigh a few bikes and found an example of how it is possible to combine low weight with top aerodynamics:
The Cervélo S5 by Jonas Vingegaard weighs 6950 grams ready to race in frame height 52 with 1x12 drivetrain. For comparison: Primož Roglič's Specialized Tarmac SL8 weighed 6920 grams on the Tour scale, but has slightly worse aero values (209 instead of 202 W). Visma | Lease a Bike's trick is familiar from last year: The 1x12 drivetrain pushes the weight close to the UCI mark of 6.8 kg. Provided the gear range is sufficient, the one-blade strategy is a good decision from a technical point of view and makes the aero racer a universal weapon. So it's no wonder that Jonas Vingegaard used exactly this bike on the first stages.
At the other end of the spectrum, our colleagues found Mathieu van der Poel's bike. His Canyon Aeroad weighed in at 8020 grams, making it significantly heavier than a standard bike. The bike of Jasper Philipsen, who has since retired, is 200 g lighter according to our weighing. This is also significantly more than the weight of the standard wheel. The extra weight invites speculation: Do the pros ride reinforced frames? The extra weight can hardly be explained otherwise. The 30 mm tyres, which are now standard, are not enough of an explanation. We have updated our list and now use the weighed weight of Mathieu van der Poel's bike.
The number of the day: 14 thousandths of a second
0.014 seconds is the fastest bike in the simulated final sprint up the finish climb, which according to our calculations is the S5 in the 1x12 setup. Converted, the mathematical lead over the runner-up is a good eight centimetres.
The next places are taken by bikes that scratch the 6.8 kg mark. Those that are more aerodynamic sort themselves further towards the front.
The (almost) complete field in the final uphill sprint*
The table shows that weight provides the basis for the sorting in the 14% steep section, but that aerodynamics also influence the ranking on the mountain.
*) The calculations are based on the bikes tested by TOUR in the laboratory and wind tunnel. The bikes at the Tour de France may differ in some details. Of course, we have not yet been able to analyse last-minute prototypes. Background to the simulation.
Our expert
Robert Kühnen studied mechanical engineering, writes about technical and training topics for TOUR and develops test methods. Robert has been refining the simulation calculations for years and they are also used by professional teams.
