The Decisive Factor: Tyres – The TOUR Tech Briefing on Stage 7 of the 2026 Tour de France

Another day for the sprinters is on the cards. 850 metres of climbing over 175 kilometres – it doesn’t get any flatter than this on this tour. The only obstacle on the route is the Cote de Beguey (1.6 km, 4.2 per cent), 34 kilometres from the finish. The sprinters’ teams will be looking to guide their fast riders over this climb. The tried-and-tested tactic is to have the sprinters lead the way into the climb; they then have the length of the peloton to drop back on the ascent. However, the distance to the finish is also long enough to bring a sprinter back should a gap open up.

At the end of the stage, a completely flat finish awaits in the heart of Bordeaux. 5,000 metres before the finish, the peloton must still cross the River Garonne, which requires a few sharp changes of direction; after that, there are no further major obstacles – the home straight on the Quai Louis XVIII is six metres wide and runs straight ahead.

The sprint teams therefore have plenty of time to get their captains into position. We can expect a fast-paced sprint finish.

​We’ve already discussed weight and aerodynamics. What other options do sprinters have for making their bikes faster?

One factor to consider is the tyres. Riders in the general classification are increasingly opting for time-trial tyres for regular stages, including those in the mountains. This is because, although the rolling resistance of modern tyres is low, it exerts a constant braking force that is proportional to speed. The faster you ride, the higher the rolling resistance – even in the middle of the peloton. Rolling resistance is not affected by slipstreams. However, it increases significantly when the road surface becomes soft, as has been the case in France over the last few days, because the road does not spring back.

Smoother rolling offers two advantages: overall, it saves a fair amount of energy, which is always a factor in a gruelling race like the Tour. The second advantage is greater speed for the same effort when it really counts – that is, in race-deciding situations.

Time trial tyres for everyone

How much faster are TT tyres than standard road bike tyres? In Tour tests, time trial tyres such as the Conti GP 5000 TT or the Vittoria Corsa Pro Speed are around 1.7 watts faster than very good all-rounders such as the Conti GP 5000 (at 35 km/h, 85 kg system).

The latest range from tyre giant Pirelli bridges the gap between all-round and TT tyres. Pirelli’s new racing tyre, the P Zero Race SL-R In the TOUR test, it performs on a par with Conti’s 5000 TT time trial tyres. The advantage of the Pirelli: The tyre is also designed as an aero tyre, which is particularly helpful when the front wheel is hit at an angle (by wind or on descents), and has a longer service life than the Conti TT, which has a particularly thin rubber compound.

Another specialist tyre is Continental’s Aero 111, which has a highly aerodynamic tread pattern. However, the tyre does not offer the same rolling efficiency as the TT model, and we have not yet seen it at this year’s Tour de France. Vittoria’s time trial tyres perform very well in terms of rolling resistance, but do not have any particular aerodynamic properties.

As far as tyres are concerned, we believe that the teams sponsored by Pirelli (Lidl-Trek, Alpecin-Premier Tech) currently have a slight advantage. Mads Pedersen and Mathieu van der Poel are among those benefiting from this.

A comprehensive look at rolling resistance

To study the effect of tyres on a sprint, we will once again simulate a hypothetical bicycle and keep all variables constant apart from the tyres. With rolling resistance coefficients ranging from 0.0025 to 0.0035, the following picture emerges for a long sprint over 250 metres:

For every 0.0001 change in the rolling resistance coefficient (equivalent to 0.8 watts at 35 km/h and a 85 kg system), the bike crosses the finish line three thousandths of a second sooner, which in turn equates to a lead of just under six centimetres. Switching from the standard Conti GP 5000 to the Conti GP 5000 TT results in a difference of around 0.0002 rolling resistance points. At sprint speed, this translates to an advantage of 3.2 watts. The time trial tyre thus provides an eleven-centimetre lead at the finish line! There have been races decided by much narrower margins.

The time trial tyre is therefore also seen as one element in the long chain of marginal gains, even in the final sprint. The theory of marginal gains holds that, taken on its own, a single factor is not a big deal, but the sum of many small details can make a significant difference. The originators of this philosophy in modern cycling were Team Ineos, who were among the first to scrutinise every detail.

The fact that the peloton is constantly racing faster (the average speed of the Tour is rising steadily) is presumably due to a combination of factors. Better equipment, better training, better nutrition and, as a result, a higher level of performance.

Number of the day: Four thousandths of a second

​But back to the sprint in Bordeaux. Today, our avatar has the same weight as Tim Merlier. The Belgian, who is one of the favourites for this type of finale, weighs 76 kg. We are simulating a sprinter over 250 metres, with a starting speed of 62 km/h.

Assuming that the team bikes perform equally in terms of rolling resistance, the highly aerodynamic Van Rysel RCR-F Pro – the bike ridden by Olav Kooij, who won the fifth stage on it – once again comes out on top in our comparison. Its lead over the Cervelo S5 is four thousandths of a second.

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

The “Aero-Power” figure shown is the power measured by TOUR in the wind tunnel as required 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.

Stage 5 Review

The fifth stage went according to plan and, as expected, ended in a bunch sprint, which Olav Kooij won convincingly.

Also noteworthy, however, was the aero performance of breakaway rider Baptiste Veitroffer from Team Lotto-Intermarché, who showcased the new Orbea Orca Aero bike over a 140-kilometre breakaway, achieving an average speed of 45 km/h on his own. Rarely has the benefit of an aero bike been demonstrated more clearly at the Tour. Our list still shows the aero rating of the previous model. The new Orca Aero is likely to significantly undercut this figure and join the ranks of the fastest bikes.

​* 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 attacks on climbs and proper final sprints. Taken together, this makes the simulation very realistic. What we cannot replicate are dynamic riding 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.