Tour de France 2015, preview: From this point on, the going gets tougher

The pressure on the overall contenders will tighten further on Sunday in a 28km (17.5-mile) team time trial between Vannes and Plumelec

Tomorrow’s time trial is the main event for Alex Dowsett (Getty)

Hard as it is to believe after such an eventful first seven days of the Tour, the most decisive stages are still to come – with this weekend’s combination of the Mûr-de-Bretagne summit finish today and tomorrow’s team time trial both vital tests for the overall favourites.

Today’s final, short, punchy ascent is only two kilometres long. But as it is the most emblematic climb in Brittany, French cycling’s heartland, victory will be both hugely prestigious in itself and a chance for the overall contenders to intimidate their rivals with a brief show of climbing prowess before the main event in the Pyrenees next week. Breton fans are expected to line the route in their tens of thousands, with young climbing star Warren Barguil a firm local favourite.

In 2011, on the Mûr’s 11 per cent slopes, Cadel Evans timed his late acceleration perfectly to claim the stage victory – and, having intimidated his rivals here, went on to win the Tour. Second was none other than Alberto Contador, Chris Froome’s key rival this year, who later claimed only a mechanical problem had prevented him from running Evans closer. However, after taking the lead early with a blazing acceleration on the race’s first summit finish at Huy on Tuesday, Froome will surely be the favourite for stage victory today.

The pressure on the overall contenders will tighten further on Sunday in a 28km (17.5-mile) team time trial between Vannes and Plumelec. As on Saturday, the time trial route is on constantly undulating, narrow Breton roads, culminating in a steadily rising final 1.5km climb of the Côte de Cadoudal.

Teams are timed collectively for their effort, with the clock only stopping when the fifth rider in the squad has crossed the line. A team, therefore, has to ensure its leader remains in their front group of five – given a lone rider cannot come close to maintaining the speed of a team as a unit, and could, if isolated at the wrong moment, lose the race.

“We’ll have a game plan which will be quite important that we stick to,” says Movistar’s Alex Dowsett, who is on his first Tour but whose huge time-trialling experience makes him a key part of overall contender Nairo Quintana’s squad tomorrow.

“It’s not going to be easy. You’re only as strong as your fifth man [over the line]. Individual time trialists don’t necessarily make good team time trialists, either – it’s more important how the team rides together. Being so lumpy a course, it’ll be interesting.”

Movistar will be among the favourites, with their aim being for Quintana to gain time on Froome and Co.

“That’s one of the reasons why I’m here, my finish line is on Sunday because after that we’re into the Pyrenees,” Dowsett says. “So far [as of yesterday morning] we’re all in good shape, I think. I’m probably the one who’s worst off, but I’m getting better.” The Essex rider crashed mid-way through stage four and is now riding with six stitches in one elbow injury.

Shifting the team time trial from its usual stage four or five slot to much later in the Tour, stage eight, could make for greater time differences, too, with some teams seriously weakened from a crash-torn first week. Sky, BMC, Tinkoff-Saxo and Movistar are all (yesterday’s stage notwithstanding) relatively intact, but other top squads have lost their time-trial powerhouses.

Trek and Etixx-Quick Step, for example, will be missing multiple world champions Fabian Cancellara and Tony Martin, both of whom abandoned the Tour injured, while Orica-GreenEdge, who won the Tour’s last team time trial in 2013, are down to six of their original nine riders. Either way, the pressure will be on the time trialists to perform at their maximum – just two days later, the race heads into the Pyrenees.