British cyclist Michael Hutchinson on Twitter: "Coach Heiko is standing a bit in front of the line - so Wiggins is just below the pace he wants. But still on 54.5kph."

Former performance director of British Cycling Sir Dave Brailsford on Sky Sports: "I'd like to think he's not thinking about the crowd at all. He'll be focusing on his pacing. Bradley thrives off big, scary, ambitious goals. So far he looks really good."

Crouched into his handlebars, wrists pointing directly forward, golden helmet on his head, Wiggins continues his dizzying spin around the velodrome. He looks comfortable, calm and consistent.

Image source, Reuters

I hope you're paying attention to this - you might not see it happen again for a long, long time.

If everything goes to plan for Wiggins, the record will stand for some time.

Jens Voigt, who briefly held the record in September, predicted: "I think he will go warp speed, like Star Trek, between 54-55km. And after that not many riders will want to try for a while."

The clock is working again by the way, which I'm delighted about, because my job would have proved very interesting without it.

So Wiggins is expected to break this down into five 12-minute sections, and we're just coming up to the end of the first of those spells.

He's clocked up 43 laps. So some quick simple maths will tell you that would equal around 215 laps. The last 12 minutes will be the quickest of the bunch though.

There is something wonderfully mesmerising about this. Wiggins, like a metronome, is swinging his way around the track with clockwork regularity.

He's on 31 laps now. Dowsett's record took 212 laps. Still a bit to go.

While Wiggins settles into his pace - here's a bit of extra reading for you.

"You're racing against history. The basis of the record hasn't really changed, it's one hour, on a track, as far as you can go."

That's Bradley Wiggins's assessment of what he's up against today.

Read more of his thoughts, as well as an intriguing breakdown of the hour record, by our very own Matt Slater.

Wiggins has very much gone for a blistering opening spell. He's almost 10 seconds ahead of Alex Dowsett's world record pace.

At least I think he is - they're having a few technical problems in London...

So, Wiggo was so keen to get under way, he's gone a bit early. Three minutes early in fact. So it's official, he's under way!

OJ Borg, BBC Radio 5 live's presenter of BeSpoke, on Twitter: "BRING THE NOISE. The Wiggins #myhour crowd have a music festival vibe. The bars are rammed. And wiggins comes out. RUCOUS."

Wiggins is on his way out, on his bike, and the crowd are lapping it up. Everybody is on their feet, clapping frantically, rock music is pumping out the PA.

It's a pretty special moment to be honest.

I can confirm the beard has gone. The haircut is very much a more cropped affair too - although I hope he'll be putting a helmet on.

Keep your guesses for the distance coming - use #bbccycling on Twitter to join in.

Stuart Mitchell: Bradley has been talking of mid 54km so i wouldn't bet against that possibly even reaching 55, my guess 54.784

Roy Horn: Brad will get 53.843 km in the hour. The high pressure and the audience will tell late on.

Matt Thorpe: 55.25km Wiggo the man to take it all the way

Bryan Saunders: I cycled 55 km around Sao Paulo in 2+ hours today, Bradley Wiggins to attempt it in 1! Hope he has less traffic!

There have been a few races already on Lee Valley VeloPark track. The capacity crowd of 5,500 was sold out in seven minutes, don't you know?

Although Wiggo will be looking at all those extra people and just seeing them as potential oxygen stealers. He'll want as much air to himself as he can get.

Alex Dowsett
Current hour record holder

How do you break the hour record? Current record holder Alex Dowsett describes his strategy.

"Everyone has ridden the hour record slightly differently. I opted for negative splits.

"For 52 minutes of the hour I was behind record holder Rohan Dennis. Rohan started out a fast pace but faded in the last 15 minutes.

"Every single lap is recorded and half a lap later I am given a hand single - the number of fingers up or down is the number of seconds I am up or down on the schedule."

Image source, Getty Images

Many wonderful things have occurred in Wolverhampton, but possibly few are as notable as James Moore's first unofficial hour record, set on a penny farthing, in 1873.

Moore travelled 22.331km, which is incredible considering he spent 20 minutes of his attempt getting on the bike (that's a lie).

Belgian legend Eddy Merckx's 49.431km in the high altitude of Mexico City in 1972 is seen as one of the greatest ever rides.

After that, it all gets a bit murky, with the UCI, in 1997, retrospectively discounting any records that weren't achieved on an old-school bike like Merckx's.

The UCI reassessed that policy last year, allowing modern race bikes to be used, and before you know it, everybody's having a crack at it.

We're seeing shots of Bradley Wiggins in the bowels of the velodrome. He's on a stationary bike, getting the legs warm.

He looks relaxed. But when has Wiggo ever looked stressed? There's a suggestion the beard may have been shaved off too - could that add an extra kilometre or two?

Alex Dowsett
Current hour record holder

We spoke to Alex Dowsett on Friday, here he talks us through the preparations for his successful hour attempt in May.

"The longest I did beforehand was a 35-minute stint. The problem is the unknowns on the day - it costs a huge amount of money to bring the room up to temperature.

"All my training sessions were done at 22 degrees centigrade, whereas in the race it was 28. We didn't know what toll that would take on my body, but it makes conditions faster.

"When I do my second attempt I will know a lot more. I know that doing 17.1-second laps in the race is like doing 17.3secs or 17.4secs in training. You wish you could do it again two days later because of what you've learned."

Image source, Getty Images

In May, Britain's Alex Dowsett became the fourth man in eight months to break the hour record, by travelling 52.937km at Manchester's velodrome.

The 26-year-old Movistar rider beat Australian Rohan Dennis's mark of 52.491km (32.89 miles), set in February.

Essex's Dowsett is a three-time national time trial champion, a Commonwealth Games time trial gold medallist, and a stage time trial winner in the Giro d'Italia.

Image source, Twitter

Chris Hoy reckons 54.458km, which is wonderfully specific. But we want your guesses, and a sentence backing up your prediction.

It's a bit like that game at the school fete where you guess the number of sweets in the jar, except there's no prizes and it's not next to the hook-a-duck stall.

Anyone who says 'I reckon it will take him an hour' will be immediately disqualified for being unfunny.

Get involved using #bbccycling, external on Twitter