Tour de France 2024 - Stage 8: Semur-en-Auxois - Colombey-les-deux-Eglises | 183.4 kilometres
The eighth stage is made for breakaways. The profile is undulating, there are many changes of direction and the metres in altitude add up to 2400 m. There will be a battle between the sprinters' teams and the breakaway riders. Whether breakaways make it through depends on the balance of power between the escapees and the controlling teams.
The last somewhat longer climb is 16 kilometres before the finish. The approach to the finish is clear, the last 2000 metres are dead straight. Up to the Teufelslappen, the road is slightly downhill, from there to the finish line the road climbs slightly with a gradient of 2 per cent. A small detail that can still make a difference. In the sprint against the slight incline, the sprint takes longer, the top speed is lower and explosiveness is less important. A sprinter like Mads Pedersen copes very well with these conditions.
Should a breakaway group prevail, at least two scenarios are possible: a sprint by the group or an attack over the last 1000 - 2000 metres. The latter would be chosen by a breakaway rider who is not a good sprinter but has the ability to stand.
Aero, Aero, Aero
What can the drivers do from a material perspective to improve their chances? As a reader of the Tech Briefing, you already know what's coming: the aerodynamics lesson...
Streamlined equipment is required for all those riding at the front, regardless of whether they are travelling in the role of controllers (of the sprinter teams), as breakaways or as final sprinters.
The greatest time advantage through technology can be realised by riders who are on their own for a long time. In other words, the breakaways. Even the breakaway king Jens Voigt rode his escapes on aero bikes with flat down tubes before this category even existed. Since then, the racing suits have improved, the bikes anyway and the handlebars have become narrower. Just look at the Trek Madone ridden by Mads Pedersen. The burly Dane rides a handlebar that is so narrow that a few years ago it would only have been fitted to a child's racing bike. The narrow handlebars serve to give the body a slightly more aerodynamic shape.
Time trial tyres for the escape
Time trial tyres such as the Conti 5000 STR TT are also used - somewhat faster than the already fast normal Conti 5000 - and still with very good puncture protection, as our tests have shown. The tyre is faster because it has a thinner rubber coating; it is more or less inherently worn.
This allows you to constantly save energy over the entire stage, even if you are hiding in the slipstream deep in the peloton. If you ride at the front, the time trial tyre gives you extra speed.
With the wheels, especially the front wheels, which are the sails of the road bike, you can also turn the speed screw. The Conti Aero 111 aero tyre introduced for the Tour makes the wheel and tyre system faster and easier to control - especially in crosswinds. As the tyre is labelled as a 29er (effectively 28 mm wide), the UCI has nothing to say if the tyres are mounted on rims with 25 mm internal dimensions, such as the Enve SES 4.5 - as 29ers are the current minimum width required for this type of rim.
The sweet spot of rim height for all-round applications is 45-50 mm profile height. High rims sail more effectively overall than low ones. Outliers who pull out all the stops go for 60 mm. All these details help to shift the odds of victory slightly in your favour.
Tactics beat technology
But whether runaways really get away is less a technical than a tactical question. Above all, it is a question of willpower. Of course, a larger group always has advantages because you can slipstream each other. The rider in second position saves around 30 per cent power. In the middle of a compact field, the air resistance drops to the knees like behind a lorry. Here, a professional rider feels almost no wind pressure and rolls in the compensation zone, even if the speedometer shows 45.
Number of the day: 1:20 minutes
In our scenario for stage 8 of the Tour de France 2024, we simulate an attack from a small breakaway group 1200 metres from the finish. It can happen that breakaway riders tactically block each other in an attack so close to the finish, because no one wants to be the first to follow so as not to jeopardise their sprint chances. Any hesitation opens up room for manoeuvre for riders who can pull away. A crack rider in this discipline needs 1:20 minutes for the last 1200 metres.
Our simulation, in which the Canyon Aeroad CFR is once again the fastest, shows the extent to which the bike helps. However, the gaps are small, with a gap of just two seconds in the calculated situation.
The (almost) entire field at a glance*
*) The calculations are based on the bikes tested by TOUR in the laboratory and wind tunnel. The bikes at the Tour de France may differ in some details. Of course, we have not yet been able to analyse last-minute prototypes. Background to the simulation.
The ranking shows the fastest bikes for the 1200 metre attack to the finish line.
Our expert
Robert Kühnen studied mechanical engineering, writes about technical and training topics for TOUR and develops test methods. Robert has been refining the simulation calculations for years and they are also used by professional teams.
