Tour de France 2025 - 12th stage: Auch - Hautacam | 180.6 kilometres | 3850 vertical metres
On the twelfth stage, the first Pyrenean peaks rise up in front of the riders and with them the first long climbs of the Tour. The cards are reshuffled, now it's no longer about seconds, but minutes.
The Col du Soulor marks the start. There are 11.8 kilometres with an average gradient of 7.3% to climb. This is followed by the short counter-climb to the Col de Bordères before the 13.5 kilometres to Hautacam with an average gradient of 7.8%.
The Col du Soulor is unrhythmic. However, it is questionable whether there will be an attack here. The GC riders will probably only test themselves on the final climb. This is tougher - in the middle section there are two kilometres to climb with an average gradient of just over 10%.
So is it time to ditch the aero bikes and switch to mountain bikes? In our simulation, we analyse the climb to Hautacam. Our avatar rides quickly up the mountain and attacks 6.5 kilometres before the finish.
The number of the day: 35 seconds
The result of our calculations: the light bikes have a tough time this year. Aerodynamic and heavy is of course not an option either: the fastest bike has a 35-second lead over a heavy aero racer on the final climb.
The ranking is once again led by the Cervélo S5, followed by the Specialized Tarmac SL8 and the Giant Propel. If the decision is made earlier than on the final climb, the lightweight aero bikes are of course the better choice as they are faster on the descents. No matter how the stage goes in detail: We see no reason today to do without aero features because of 200 grams, the mountain is not steep enough for that.
Accordingly, it would not be necessary for Tadej Pogačar to switch from his Y1Rs to the V5Rs. However, the bikes are very close to each other in our calculations, so there could be other reasons for switching bikes.
The (almost) complete field at a glance*
The table shows: On the final climb of the twelfth stage, the bikes that combine low weight and good aerodynamics are in the lead.
*) 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.
