Tour de France Femmes 2025 - Stage 6: Clermont-Ferrand - Ambert | 123.7 kilometres
The first mountain stage of the Tour covers 123.7 kilometres and 2,475 metres of elevation gain. The central climb to 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 slipstreaming plays a significant role. Around 50 watts are then required in the leading position just to overcome 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, the probability of major changes in the overall classification is low. However, as the time gaps are small overall and the stages are short, breakaway riders will not get much of a run. The favourites for the overall victory may therefore also compete for stage victory.
However, the basic strategy of the GC riders will probably be defensive: the motto will be not to 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 bikes?
Since the climbs are not particularly steep and the race will be fast, aero equipment is the weapon of choice on this mountain stage. For breakaway riders, it is particularly essential to save every ounce of energy they can. Anyone who wants to survive alone or in a small group must do everything they can to cut through the wind as easily as possible. From clothing to bikes, everything should be optimised for speed. Aero clothing - from time trial socks to aero gloves, aero suits and aero helmets - the full range. Aero wheels, aero tires, and a freshly waxed chain are further ingredients for minimising riding resistance. When it comes to tyres, breakaway riders can take a risk and choose time trial tyres. These offer poorer puncture protection but save another 2-3 watts.
For riders in the overall classification, the situation is similar - except for the tyres. If you're riding defensively, we would rate the better puncture protection of a normal tyre higher than the small savings offered by a time trial tyre. This is because a puncture at the wrong time can lead to a loss of ground in the overall classification and therefore has a more noticeable impact.
Another tyre option that also increases rolling resistance is rain tyres. Schwalbe rain tyres have already been spotted by the editors in the paddock. If the weather forecast is bad, tires that inspire 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 tyres can feel very different at the limit.
In today's stage finale, however, the final descent towards the finish line does not look particularly complicated. If an attack is successful, it will be more about pedalling power and aerodynamics. Today's simulation revolves around the final descent. How much time can be gained here on the wheels?
The number of the day: 21 seconds
In our simulation, the fastest bike gains a 21-second lead over the slowest bike on 12.1 kilometres. Bicycle technology therefore plays a role in downhill attacks.
An overview of the (almost) complete field
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 s due to slightly more propelling mass.
Our expert
Robert Kühnen studied mechanical engineering, writes for TOUR about technology and training topics and develops testing methods. Robert has been refining the simulation calculations for years, they are also used by professional teams.
