Tour de France 2017: Stage 18 Preview

The 2017 Tour de France goes above 2,000m four times in the whole race, and it does it all in the space of two days. If yesterday was bad, then today could be worse as the finish line is right up in the dead air at 2,360m above sea level.

The route describes the shape of a horseshoe and the first section should be of little consequence to the peloton, however weary it is at this stage, because it travels south with more down than up along the Durance valley road. The route makes an excursion along the eastern shore of the Lac de Serre-Ponçon and the cat-three Côte des Demoiselles Coiffées before picking up the River Urbaye and heading upstream. It's a very gradual climb up the valley road through Barcelonette and Jausiers – the sort of terrain where big groups get away – before turning off left at Saint-Paul-sur-Urbaye for a rare return to the Col du Vars, last used in the Tour in 2000, but a regular feature of the mammoth north-south stages of the 1950s and 60s. The Vars is at its most testing during a long middle section that runs for 2km at about 10 per cent. The descent isn't particularly technical but it does bunch up towards Guillestre at the bottom. Finally, the race makes for the big event, not just of the stage but possibly the Tour: the 14km Col d'Izoard. Purists may baulk at finishing a stage on a col -– what goes up should come down after all – but the toughness of the Izoard, with long sections upwards of nine per cent and a short section of 14 per cent near the top, just after the other-worldly dolomite rocks of the Casse Déserte, will provide the penultimate stratification of the GC. The King of the Mountains jersey will also be decided here. It's the only stage where there are double points for the winner.

"I think the Col d'Izoard on paper isn't that long but it is steep from what I remember. This stage comes the day after the biggest climbing stage of the Tour and I think already the guys would have started the previous stage going into the reserves. Col d'Izoard is going to be another one where they'll go into the reserves and if someone is having a bad day or a good day, maybe it will be a day of drama in the GC

"I think it is most likely that a breakaway will contest the stage as everyone will be pretty exhausted by the time to get to stage 18. If someone is not climbing well, they will be pushed to their limit on the climbs anyway. It's a delicate balancing act as you certainly don't want to lose any time on the climbs but if you limit your losses and save some energy for the time trial that would be ideal. I expect after the solid finish and several hard days close together in the third week that it will be where the third week will count for a lot."