Tune in as Sir Bradley Wiggins attempts to break the UCI Hour Record at the Velodrome in the Olympic Park.
The record, considered one of the most prestigious in cycling, is currently held by Alex Dowsett.
Dowsett achieved the feat back in May, and he'll be watching nervously as his fellow Briton takes off at 18:30 this evening.
Speaking after setting the record last month, Dowsett said that "the first 30 minutes were easy compared to what I expected but the last 10 minutes were a bit grippy."
His record stands at 52.937km - 32.894mph - over the hour. But what does the challenger himself have to say?
"It's such a historic record when you think about the people who have gone for it before," said Wiggins. "The likes of Eddy Merckx, Francesco Moser, (Fausto) Coppi, (Jacques) Anquetil - some of the greatest cyclists who have ever lived
"And as a Tour de France winner, and Olympic and World time-trial winner, I almost felt a little obliged to go for it.
"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."
