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 elevation gain adds up to 2,400 metres. There will be a battle between the sprinter teams and the breakaways. Whether breakaways get through depends on the balance of power between the escapees and the controlling teams.
The last slightly longer climb is 16 km before the finish. The approach to the finish is clear, the last 2,000 metres lead straight ahead. Up to the 1000 metre mark, the road is slightly downhill, from there to the finish line the road climbs slightly with a gradient of 2 percent. 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 1,000 - 2,000 metres. The latter would be chosen by a breakaway rider who is not a good sprinter, but has the qualities to stand up.
Aero, Aero, Aero
What can riders do to improve their chances from a material perspective? 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, whether they are riding in the role of controllers (of sprinter teams), breakaway riders or finishing sprinters.
The riders who can gain the biggest time advantage through technology are those who are on their own for a long time. In other words, the breakaway riders. 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 children'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 - slightly 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 save energy throughout the entire stage, even if you are hidden 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. Since the tyre is labelled as a 29er (effectively 28 mm wide), the UCI can't say anything if the tires are mounted on rims with 25 mm internal dimensions, such as the Enve SES 4.5 - because 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. Overall, high rims sail more effectively than low ones. Outliers who pull out all the stops go for 60 mm. All these details help to shift the odds of victory a little in your favour.
Tactics beat technique
However, whether breakaways 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% power. In the middle of a compact field, the air resistance drops to the knees like behind a truck. Here, a professional rider feels almost no wind pressure and rolls in the compensation zone, even if the speedometer shows 45 km/h.
Number of the day: 1:20 minutes
In today's scenario, we simulate an attack from a small breakaway group, 1,200 metres before 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 ruin their sprint chances. Any hesitation opens up space for riders who can pull away. A crack rider in this discipline needs 1:20 minutes for the last 1,200 metres.
Our simulation, in which the Canyon Aeroad CFR is once again the fastest, shows to what extent the bike helps. The gaps are small, however, with a gap of just two seconds between the field 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 also not yet been able to examine last-minute prototypes. Background to the simulation.
The ranking shows the fastest bikes for the 1,200 metre attack to the finish line.
Our expert
Robert Kühnen studied mechanical engineering, writes for TOUR about technology and training topics and develops testing methods. Robert has been refining the simulation calculations for years, they are also used by professional teams.
