Tour de France 2025 - Stage 10: Ennezat - Le Mont-Dore Puy de Sancy | 165,3 Kilometers
The mountainous part of the Tour begins in the Massif Central. On the national holiday, the tenth stage leads over eight categorized mountains. Even though there are no super-long or super-hard climbs, the riders will have to cover 4,450 meters of elevation gain, which will tear the field apart.
Strong climbers will try to break away, and the GC contenders will also be under pressure. Anyone having a bad day could lose valuable time today, or in extreme cases even lose the Tour.
If the favorites stay together, a shoot-out on the final climb is to be expected: the final climb is 3.3 km long with an average gradient of 8 %; at the beginning there is a section with a 12 % gradient. Ideal for attacking there. Which bike is best for such a big day?
Given the profile, pure aero bikes will probably stay in the truck. But is it worth being as light as possible and compromising on aerodynamics? For example, will Tadej Pogačar park his aero racer and opt for the presumably lighter V5Rs?
The number of the day: eight seconds
Our simulation shows that 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 entirely irrelevant either. However, due to the short final climb, the differences are small: only eight seconds separate the slowest and fastest bikes on the final climb.
Mathematically, Tadej Pogačar's V5Rs climbing bike is also slightly slower than his Y1Rs. If there is no shoot-out on the final climb and the race for the overall classification heats up beforehand, the aero bike would also be the better choice because it is faster on descents and gentler climbs.
The fact that the organizer is also expecting a fast race is shown by the pace chart, which forecasts 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 optimized. 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 machines used in the Tour de France may differ in detail. Of course, we were not yet able to examine last-minute prototypes. Background information on the simulation.
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.
