The second stage begins flat as a board. From kilometre 76, however, there are some tough ramps awaiting the riders - third and fourth category climbs. In principle, this is puncheur terrain. Riders who can really hold on for a few minutes have the best chance of pulling away. Pure sprinters, on the other hand, will not like the finale, as the climb to the Basilica of San Luca has to be tackled twice at the end, a beastly hill with a gradient of up to 19 per cent.
On the approach to these ramps, aerodynamic material has an advantage, that's clear. But what does it look like on the Cote de San Luca, where the preliminary decision is likely to come from a more or less large group?
What effect does the material have on the riding times on this decisive climb? Our simulation provides the answer. We let the riders virtually slam into the climb and then up it in one go and look at the effects on the riding times in the individual sections of the climb in fine detail.
With the heaviest bike in the field, a rider loses five seconds on the Cote de San Luca compared to a bike with the minimum weight of 6.8 kg. Five seconds means around 30 metres behind at the end of the climb.
*) 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 simulation shows that bikes close to the minimum weight cluster at the top of the calculated riding times on the Cote de San Luca - which is hardly surprising. What is more surprising is that the time differences are not greater. But the gradient eases a little twice and the uphill speed reaches over 30 km/h at times, so aerodynamic forces are at work even on this steep cliff.
The fastest bike in this scenario is the Specialized Tarmac SL8, four tenths of a second ahead of the Giant Propel Advanced SL. The slightly lighter Giant TCR takes third place in our mountain simulation due to its weaker aerodynamics.
From the crest to the finish line, there are still 12.6 kilometres to go, mostly downhill and flat, with two small waves as counter-climbs. A lead of just a few seconds, which optimal cycling technique can provide, will not be enough to keep the chasers at bay given the distance. Technique is therefore at most the tip of the scales, the legs are decisive.
In addition to leg power, aerodynamics will once again be the most important factor in the rest of the finish. Should a group sprint, the same applies, and the aero card will still be the winner.
To summarise: If you want to ride for the stage win, you need a bike that is as light as permitted at 6.8 kg and yet as aerodynamically shaped as possible.
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.