Cervélo once again: The fastest bike for Stage 8 of the Tour de France Femmes

The eighth stage gives the GC riders a chance to catch their breath. The route runs from Sisteron to Nice, covering 171.9 kilometres. However, the topographical challenges are minimal. The Col de Toutes Aures (6.4 km, 3.1 per cent) after 76 kilometres is the highest point; from there, the route descends for just under 100 kilometres towards the sea. Any early breakaway riders can easily be reeled back in on the long ride to the coast. The fastest average speed in the stage profile: 46 km/h. That pretty much says it all.

However, two climbs that are barely visible on the route profile, just before the finish, provide the perfect opportunity to launch an attack and shake off the pure sprinters. The Côte de la Ginestière, ten kilometres from the finish, is only 152 metres high, but with a brief 13 per cent gradient, it is steep enough to split the peloton.

It therefore looks set to come down to a battle between the sprinters and the late breakaway riders.

​The number of the day: 25 seconds

Let’s imagine an attack on the final short climb. Which bike would be best for a breakaway rider to pull away on?

You’ve probably guessed it, because the bike has been out in front in every scenario so far: the Cervélo S5 clocked the fastest time. Aerodynamics are most important on the flat run-in to the finish after the hill.

The lead over a lightweight bike is 25 seconds.

However, a sprint finish seems more likely to us than a breakaway. Lorena Wiebes is the top favourite. If her team gets her to the front going into the final climb, she’ll only have to go flat out for two minutes to stay with the pack. That’s something the top sprinter is capable of.

An overview of the (almost) full line-up*:

* Simulation calculations

Based on our own wind tunnel tests, we carry out simulation calculations for the Tour de France tech briefing. How TOUR tests: Aero road bike test in the wind tunnel.

We are investigating which wheels can offer a technical advantage in which situations. The variables we can control in the simulation include wheel weight, rider weight, the inertia of the wheels, the drag coefficient, the rolling resistance coefficient and the efficiency of the drivetrain.

To model ride times, we use realistic power outputs and weights for the riders, combine these with our wind tunnel data, and have the riders race virtually along selected sections of the route, which we extract from the official route data; the derived elevation profiles are key to this. The modelling also includes bends, which we can brake for realistically, and adjustable power profiles for different types of riders. This allows us to distinguish between hill climbs and proper final sprints. Taken together, this makes the simulation very realistic. What we cannot replicate are dynamic handling effects such as the individual behaviour of the wheels on different surfaces.

The journey times calculated for the sections of the route that are decisive for the race highlight the influence of the wheels – provided that the riders always behave in the same way in a given scenario.