Tour de France Tech Briefing: Which road bike will win Stage 20 to Alpe d’Huez?

​The world’s best cyclists will be competing in the Tour de France until 26 July. Victory and defeat on the roads of France are decided not only by the riders’ legs, but also by their equipment. The TOUR Tech Briefing for Stage 20.

Final Stage, Part 2: The finish is once again at Alpe d’Huez, though not via the famous 21 hairpin bends, but approaching from the east via the Col de Sarenne. From there, it is a further 14.4 kilometres of undulating terrain to the finish.

Stage 20 is the toughest of the entire Tour. There are 5,650 metres of climbing to tackle. This means the stage has the potential to shake up the general classification. Halfway through, the riders face the ‘roof of the Tour’, the Col du Galibier, at an altitude of 2,631 metres. They must tackle a 35-kilometre continuous climb whilst breathing rather thin air.

Anyone having a bad day today could find themselves trailing by several minutes before they’ve even reached the final climb.

We’re expecting the final battle for the overall classification. The podium should be decided once the race has finished.

​Which material for the final shoot-out?

Who has the best chance, in terms of equipment, when the battle between the leaders breaks out as early as the Galibier?

We’re simulating a heroic move – an attack right at the foot of the Col du Télégraphe, 95 kilometres from the finish.

Which bike would be best for this? A lightweight one or an aero bike? Do you know the answer?

Number of the day: 20 seconds

The cycling podium for the 95-kilometre breakaway:

2nd place: Specialized Tarmac SL9

3rd place: Colnago Y1Rs

20 seconds is the Cervelo S5’s lead over the second-placed Tarmac SL9. Aero bike beats all-rounder on the Tour’s toughest mountain stage!

However, which bike crosses the finish line first at Alpe d’Huez will depend on the rider.

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 rider weights, 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.