Chris Froome is looking solid and is on course to extend his GC lead.

He crosses halfway in fifth place, 32 seconds off the pace - not a single GC contender is ahead of him at that point on the course.

Nairo Quintana is dropping too - he comes through the halfway point in 24th place.

You would not expect Chris Froome to be that low down - Nairo needs to start moving.

Here comes Richie Porte to the finish line. He's had a horrible last two thirds of a time trial and is down in 15th place.

That looks good for Chris Froome.

Richie Porte, 11th in the GC, is the only yellow jersey contender to go quicker than Froome at the first checkpoint.

He's 2mins 22secs adrift of the race lead - but he also faded as he got deeper into this time trial.

Chris Froome is through the first time check - and he's the quickest of the top five GC contenders.

The yellow jersey man is sixth quickest at 7km and 17secs off the lead pace.

Richie Porte was looking competitive at the first time check, but at the 28km mark he's 2mins 3secs off the pace down in 15th.

Image source, EPA

I enjoyed this tweet from Greg Henderson - it highlights the gap in speed between time trial specialists and the rest of the pack.

Above is a brilliant picture of the moment Rohan Dennis (right) went past the New Zealander.

Bauke Mollema comes through the first time check in 10th, Nairo Quintana is 17th, 50secs off the pace.

A really impressive time trial from Geraint Thomas who is up in fifth place as it stands.

He overtook Pierre Rolland on his way through.

Here's the top three so far today. None of them are yellow jersey contenders:

Tom Dumoulin leads in a time of 50mins 15secs

Nelson Oliveira +1min 31secs

Jerome Coppel +1min 35secs

Chris Froome pedals through a few puffs of smoke - I assume they're from flares. Stupidity of the highest measure.

After going through the first checkpoint in second, Richie Porte has drifted as he hits the second time check - he's down in 12th.

Chris Froome launches off the ramp to plenty of whoops and cheers from the crowds lining the streets.

Now, we just wait...

Rob Hayles
Former GB cyclist

I can assure you this Tour is not over yet. The final week is horrendous in terms of the amount of climbing. Bauke Mollema has moved himself into third – he seemed to be climbing better than Nairo Quintana yesterday and if he can have a good time trial you never know. I think the guy that could drop out today is young Adam Yates. He could very well fade away today – but he has been climbing very well.

Adam Yates, the Briton who for a short while was in the yellow jersey position yesterday, lines up his bike on the ramp. He looks a bit concerned with something on his bike. Not the best preparation.

But away he goes.

The yellow-shirted figure of Chris Froome looms behind him.

Nairo Quintana looked out of sorts yesterday - he was blown away when Froome, Porte and Mollema zoomed up Mount Ventoux.

The Colombian is 54 seconds behind Froome and starts his time trial.

Bauke Mollema who, like Porte, was caught up in that collision with the motorbike yesterday, is fourth in the GC and is the latest man on the course.

No time trial glories to speak of for the Dutchman - maybe today will be the day he finds his time trial mojo.