Alberto Contador is about two minutes off the yellow jersey group after his mechanical.

Now that's over, we can turn our attention to the GC. Meanwhile, Thibaut Pinot has finished.

Image source, Reuters

A wonderful ride and a wonderful beard. The Giant rider Simon Geschke nails the biggest win of his career by winning stage 17. What a grin that is.

Andrew Talansky is over 30 seconds later.

Image source, @letour

Now, this could get spicy. Movistar riders Nairo Quintana and Alejandro Valverde have been joined by Adriano Malori and Jose Herrada in that group with Froome and Nibali. Can they make those numbers work?

Simon Geschke has 1.5km to hold on - Andrew Talansky has the gap down to about 40 seconds, but is slowing.

Froome, Valverde, Nibali and Quintana are bunched together. This is what you pay your admission fee for. Can any of them shrug off the Team Sky GC leader on the final ascent?

Image source, AP

Matt Slater
BBC Sport

"We are hitting warp speed, folks! The descent of the Col d'Allos is not an opportunity to get your breath back, it is a physical and mental challenge all of its own. The final ascent to Pra Loup could even be a relief.

"Thibaut Pinot's descending issues are well documented and he is seeing a chance of victory disappear as fast as the trees that are flashing by his ears.

"But they are all on the edge here and as Alberto Contador has just discovered, even good descenders get it wrong sometimes.

"And that is another reason to commend Chris Froome on what has been a fine all-round ride. So far."

The final ascent to the finish, and Simon Geschke has Andrew Talansky in pursuit. But the gap is 59secs with 4km to go - you'd expect the Germasn to hold on.

The thin mountain air seems to be playing havoc with the riders. Simon Geschke, who leads by almost two minutes with 7km remaining, almost flicks into his own support car. Bonkers.

Vincenzo Nibali has made a break on the descent. Chris Froome has gone with him but has no team-mates. Alejandro Valverde is there too. 

Image source, Getty Images

I suggest you get any toilet breaks, tea-making and breathing done now. This is about to get zesty.

Alberto Contador looks to have had a mechanical and there's a bunch of Tinkoff-Saxo riders trying to help him out.

Thibaut Pinot's wobble seems to have addled his brain. He's been sucked in by Andrew Talansky and the American passes with ease.

Pinot has had a nightmare, but to be fair, he was a few inches from falling off a mountain a few moments ago.

Image source, @letour

Rob Hayles
Former GB cyclist

 "Richie Porte has come back right at the perfect time. This will play on the other rider's minds. They thought they had lost Team Sky riders and then there's Porte. "

Team Sky are either tactical geniuses or the jammiest team in the world. Nairo Quintana's break is stopped short as he finds Richie Porte up the road, who had dropped off the chase group and was able to hold back the Colombian to ensure Chris Froome could stick.

Here we go, Nairo's on the move...

Image source, Getty Images

Pinot was straight up and back on the bike and stays second. A terrifying slip though, with just a small wooden plank on the edge of the road the defence between Pinot and a drop down the mountain.

Ouch!published at 15:39

15:39

Oh my days, Thibaut Pinot, what are you doing? He's on the descent, hits a left-hand turn, and the wheels just kink below him and he hits the tarmac.

In that peloton it's Astana who are dragging the group along. Vincenzo Nibali is showing a turn of pace that has been missing so far on the Tour. The yellow jersey of Chris Froome bobs around just behind them, but Geraint Thomas looks like he might be slipping off the back. This is real leg-killing stuff up the Col d'Allos.

Image source, AP