Tour de France Femmes 2025 - Stage 6: Clermont-Ferrand - Ambert | 123.7 kilometres | 2475 vertical metres
The first mountain stage of the tour covers 123.7 kilometres and 2475 metres in altitude. The central climb up the Col du Béal is long, but not steep. The average gradient is 5.6 per cent. This means that the uphill speed will be around 25 km/h at a brisk pace. This is so fast that the slipstream plays a relevant role. Around 50 watts are then required in a leading position just to overcome the air resistance. If there is also wind, it can be even more. A lot of energy can therefore be saved on the rear wheel.
Accordingly, there is little chance that the overall classification will change significantly. However, as the overall time gaps are small and the stages are short, breakaways will not get much of a run-out. The favourites for overall victory may therefore also be in contention for the stage win.
However, the GC riders' basic approach will probably be defensive: the motto will be: don't lose any time.
The central climb is long, but not steep. No favourite is likely to attack here.
What does the stage profile mean for the wheels?
As the climbs are not particularly steep and the race will be fast, aero equipment is also the means of choice on this mountain stage. For breakaway riders, it's particularly essential to save every grain of grain that can be saved. If you want to survive alone or in a small group, you have to do everything you can to go as light as possible through the wind. From your clothing to your bike, everything should be optimised for speed. Aero clothing - from time trial socks to aero gloves, aero suit and aero helmet - the full programme. Aero wheels, aero tyres and a freshly waxed chain are further ingredients to minimise riding resistance. When it comes to tyres, breakaway riders can take a risk and choose time trial tyres. These have poorer puncture protection, but save another 2-3 watts.
The situation is similar for the riders in the overall classification - except for the tyres. If we were to take a defensive stance, we would weigh the better puncture protection of a normal tyre higher than the small savings offered by the time trial tyre. After all, a puncture at the wrong time can lead to a drop in the overall standings and therefore has a more noticeable impact.
Another tyre option that also increases rolling resistance is rain tyres. Schwalbe rain tyres have already been identified by the editors in the paddock. If the weather forecast is bad, tyres that provide more confidence can increase safety on descents - interesting both for riders who have a problem with descents and for those who specifically attack downhill. We know from our tyre tests that the tyres can feel very different at the limit.
In today's stage finale, however, the last descent towards the finish doesn't look particularly complicated. If an attack is successful, it will be more about pedalling power and aerodynamics. The simulation of the day revolves around the last descent. How much time can be gained on the bikes here?
The number of the day: 21 seconds
In our simulation, the fastest bike gains a lead of 21 seconds over the slowest over 12.1 kilometres. Bike technique therefore plays a role in the downhill attack.
The (almost) complete field at a glance*
The table shows the simulated riding times for the final 12.1 kilometres, which are mainly downhill. Unsurprisingly, aerodynamic bikes are in the lead. A little excess weight even helps. The Canyon Aeroad overtakes the Cervélo S5 by 0.2 seconds due to slightly more propelling mass.
*) 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.
