Tour de France 2025 - Stage 10: Ennezat - Le Mont-Dore Puy de Sancy | 165.3 kilometres | 4450 vertical metres
The mountainous part of the tour begins in the Massif Central. On the bank holidays, the tenth stage leads over eight categorised mountains. Even if there isn't a single super-long or super-hard climb, there are 4450 metres of altitude to cover and the peloton will be tattered.
Strong climbers will try to break away and the classification riders are also under pressure. If you have a bad day today, you could lose valuable time at the very least, and in extreme cases even lose the Tour.
If the favourites stay together, we can expect a shootout on the final climb: The final climb is 3.3 km long with an average gradient of eight per cent; there is a 12% section at the start. Ideal for attacking there. Which bike is best for such a big day?
Given the profile, the pure aero bikes will probably remain in the truck. But is it worth being as light as possible and compromising on aerodynamics? Will Tadej Pogačar, for example, park his aero racer and opt for the presumably lighter V5Rs?
The number of the day: eight seconds
Our simulation shows: The Cervélo S5 in a 1x12 setup is the fastest bike on the final climb, followed by the lightweight all-rounders Tarmac SL8 and Giant Propel. Weight is important, but aerodynamics are not completely out of the question. However, due to the short final climb, the differences are small: only eight seconds separate the slowest and fastest bikes on the last uphill section.
Mathematically, Tadej Pogačar's V5Rs climbing bike is also slightly slower than his Y1Rs. If it doesn't come to a shootout on the final climb and the race for the overall classification is already underway, the aero bike would also be the better choice as it is faster on the descents and the gentler climbs. The fact that the organisers are also expecting a fast ride is shown by the march table, which envisages an average speed of up to 41 km/h.
The (almost) complete field on the final climb*
The table shows: Weight counts on the final climb, but not at any price. Without exception, the bikes in the top five places are also aerodynamically optimised. Overall, however, the differences are small. They are more important for the daily ranking than for the overall classification.
*) 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.
