Race leader Geraint Thomas expects Wednesday’s 65km stage to be ‘massively decisive’ in his battle with Chris Froome and Tom Dumoulin. Photograph: Marco Bertorello/AFP/Getty Images
There have been short stages in the Tour de France before but few as critical as Wednesday’s 65km mountain stage from Bagnères-de-Luchon to the top of the Col de Portet in the Hautes-Pyrenees. But why is this stage, the 17th in the 2018 Tour, so different to the usual Alpine and Pyrenean stages?

First is the distance. This very fast route, the shortest in the Tour’s modern era, has been likened by some in the race convoy to a “team time trial” or a “criterium in the mountains”. Criteriums are the city centre circuit races ridden throughout France, usually at high speeds and with no quarter given.

The difference here is the terrain, which includes a start line at the foot of the steep climb to the Col de Peyresourde. Second is the absence of any neutralised zone, or rolling start. This means the riders will race from the start line, unlike in all other races when there is a départ fictif, or false start, and a few kilometres of neutralised riding before the flag is dropped at the départ réel – the real start.

Third is the F1-style grid, sited at the foot of the first climb, in which the yellow jersey will start in pole position and the 19 closest-placed riders on the overall standings will line up in order behind him. The rest of the peloton will be held in pens, cyclocross-style, and then start after the 20 riders at the head of the standings.

But most teams, while welcoming the initiative, don’t see it as radically changing the way the stage is raced. “This is going to be a very, very fast stage,” the Team Sky sports director, Nicolas Portal, said. “That’s as much because of the distance as anything. We may ride an hour in the morning and then do a very long warm-up before the stage.”

“Some will need a longer warm-up than others,” Adam Yates’s sports director, Matt White, said. “Half the peloton will hate the start tomorrow, especially most blokes over 65kg. It’s a really hard start for the non-climbers.

“Everybody will be on the home trainer, as usual for these hill starts,” White said. “If you’d told me 10 years ago that we’d see professionals on the home trainer before the start of every Tour stage, I would have laughed.

“We never had stages like this before and I think it’s a great idea. They’re trying some new ideas and I think it’s good to mix it up. The sport’s changing.”

Tom Southam, of the Education First team, expected attacks from the main contenders from the start.

“I think this stage will be decided pretty quickly,” he said. “It will be like a team time-trial. With Rigoberto Urán gone, we have no overall contender. So our only hopes are breakaways, but given the nature of this stage, there’s no hope of that at all.”