TOUR Tech Briefing: Tour de France 2026 – The best bike for breakaway riders on Stage 9

​From 4 July to 26 July, the world’s best cyclists will be competing in the Tour de France. Victory and defeat on the roads of France will be decided not only by the riders’ legs, but also by their equipment. The TOUR Tech Briefing for Stage 9.

The ninth stage is classic breakaway territory, featuring a multitude of short climbs that add up to 3,300 metres of elevation gain. Halfway through the stage, a Category 2 climb presents the toughest challenge (3.8 km, 7.7%).

The climbs aren’t particularly steep. Nevertheless, riders who are good climbers have an advantage. After eight stages, fatigue is already starting to take its toll.

In today’s simulation, we’ll run through the performance factors a 60 kg rider can expect on today’s stage if he launches a breakaway 115 kilometres from the finish.

As the minimum weight is set at 6.8 kilograms, lighter riders are, in theory, more affected by differences in weight than more athletic riders. This also raises the question of just how light the bikes could actually be if the UCI’s weight limit did not exist.

The lightest production bikes in the world weigh just under six kilograms. With some tuning, a total weight of five kilograms is also achievable. However, such bikes have virtually no aerodynamic qualities.

Would they be competitive on a stage like today’s? To find out, we’re also entering a hypothetical lightweight bike with an assumed weight of five kilos into the race (235 W aero power at 45 km/h).

Result: Our ridiculously light, fictional model, with a total weight of five kilograms, comes second from last in today’s ranking, with a ride time of 2:56:49 hours. A bike significantly below the minimum weight would not be an advantage for today’s stage.

Number of the day: 9.5 seconds

​As expected, a rider weighing 60 kilograms benefits more from a lighter bike than a heavier rider. This is evident from today’s rankings. The Cervelo S5, at its minimum weight, outperforms the more aerodynamic but heavier Van Rysel RCR-F Pro by 9.5 seconds.

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

​The table shows that, for lighter riders, the combination of excellent aerodynamics and minimal weight is the best way to succeed in a long breakaway.

The “Aero-Power” figure shown is the power measured by TOUR in the wind tunnel to overcome the aerodynamic drag of the bike and a dummy with moving legs at 45 km/h. For the simulation, we mathematically add the rider’s upper body and scale the drag to the actual race speed.

​* 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 influence 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 attacks on climbs and proper final sprints. Taken together, this makes the simulation very realistic. What we cannot replicate, however, are dynamic driving effects such as the individual behaviour of the wheels on different road 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.