Danish champion Kasper Asgreen is going fairly well but has just gone through the second time check 55 seconds back on Remi Cavagna.

Cavagna has opted not to switch to his road bike.

He passed the second time check 1min 50secs faster than Tony Martin in second.

Woosh.

Remi Cavagna is absolutely blasting past riders who started before him. That must be so demoralising.

The French TT champion has aced the flat section but is now onto the climb up La Planche des Belles Filles.

Can he climb well enough to post a time that sees him contend for the stage win?

Sam Bennett, clad in his all green skinsuit, is about to finish.

The Irishman stops the clock at 1hr 5mins 55secs. No danger of missing the time cut there so job done.

He'll be targeting a second stage win of the Tour on the Champs-Elysees tomorrow, but first aim will just be making sure he secures that green jersey.

Stay close to Peter Sagan - or better yet, beat him - at the intermediate sprint and Bennett will be pretty much there.

The 36.2km of time trialling today means the 2020 Tour features the lowest total of time trial kilometres since 1934, the year time trials were first introduced to the Tour.

Somwhere Bradley Wiggins is shaking his head and tutting.

There was 101.1km of time trialling in his 2012 Tour victory.

B&B Hotels-Vital Concept rider Maxime Chevalier has just set a new fastest time of 1hr 1min 57secs.

That could stick for a while, giving the young Frenchman some time in the hot seat, where the leader sits until they are beaten.

Roger Kluge's Lotto Soudal team-mate Frederik Frison has set the new fastest time at 1hr 4mins 17secs.

Green jersey Sam Bennett is through the first two time checks on the road.

The Irishman is just looking to finish inside the time cut today.

He leads Peter Sagan by 55 points, with a maximum of 70 points on offer tomorrow (Sagan isn't going to win any points today).

Bennett just needs to mark Sagan tomorrow to become the first Irishman since Sean Kelly in 1989 to win the green jersey.

Lanterne rouge Roger Kluge - the last man on GC in the Tour - is the first rider to come to the finish.

The German has stuck with his TT bike all the way up and has to drag him and it up this brutal final rise.

He comes home in 1hr 4mins 25secs. That won't last for long.

Expect the winner to clock about 55 minutes or so today.

Tony Martin doesn't look to be going great guns today. The German has done a superb job supporting Primoz Roglic in this Tour and knows this isn't a time trial that suits him.

Remi Cavagna, however, is flying. The French TT champion has just gone quickest at the first time check.

And Kasper Asgreen has just gone through second, 17 seconds back on his Deceuninck-Quick-Step team-mate.

We've got a fair while until the top 10 on general classification get underway but some outside shouts for the stage win are already on course.

German time trial champion Tony Martin, who has won four world TT titles, has set off. The final climb could be too tough for him to trouble first place today though.

Likewise Remi Cavagna, the French TT champion. He went on a solo 100km break yesterday so may be a bit tired and isn't the best pure climber but can get over lumpy terrain well.

His Deceuninck-Quick-Step team-mate Kasper Asgreen may be a better shout. The Danish TT champion is also on course now.

Australian sprinter Caleb Ewan has given us his answer to that last question.

The Lotto Soudal rider has indeed switched to his road bike for the final climb.

He's looking to conserve as much energy today, while still making sure he finishes inside the time cut, which will be set at 25% more than the time of the stage winner.

Ewan is hoping to win on the Champs-Elysees for the second year in a row tomorrow.

A time trial with a big sting in the tail.

Largely flat with a few rises for the first 30km before a brutal climb up La Planche des Belles Filles.

It starts at 13% gradient, drops to 11%, flattens out a bit, but then kicks up to 20% for the finish.

It poses plenty of problems including do you stick with your time trial bike all the way up or get your team car to come up and switch to a road bike?

Plenty of the favourites have kept their cards close to their chests on which way they'll go.

Image source, Tour de France

Primoz Roglic leads fellow Slovenian Tadej Pogacar by 57 seconds in the yellow jersey.

That's likely to be more than enough of a buffer - in fact Roglic could well extend that lead and is one of the favourites for the stage win.

Pogacar did beat Roglic in the Slovenian national time trial championships this year - but only by nine seconds.

Roglic would have to have a very bad day and Pogacar a very good one for the yellow jersey to change hands today.

But you never know...

1. Primoz Roglic (Slo/Jumbo-Visma) 83hrs 29mins 41secs

2. Tadej Pogacar (Slo/UAE Team Emirates) +57secs

3. Miguel Angel Lopez (Col/Astana) +1mins 27secs

4. Richie Porte (Aus/Trek-Segafredo) +3mins 06secs

5. Mikel Landa (Spa/Bahrain McLaren) +3mins 28secs

6. Enric Mas (Spa/Movistar) +4mins 19secs

7. Adam Yates (GB/Mitchelton-Scott) +5mins 55secs

8. Rigoberto Uran (Col/EF Pro Cycling) +6mins 05secs

9. Tom Dumoulin (Ned/Jumbo-Visma) +7mins 24secs

10. Alejandro Valverde (Spa/Movistar) +12mins 12secs

Welcome to live coverage of stage 20 of the 2020 Tour de France.

One final test for the general classification riders.

And it's a tough one - a 36km individual time trial that culminates in a brutal 5.9km climb at an average 8.5% gradient up La Planche des Belles Filles.

Primoz Roglic leads by 57 seconds, knowing a strong showing today will see him secure his first ever Tour title.