Manchester - British cyclist Alex Dowsett set a new world hour record by completing 52.937 kilometres at the Manchester Velodrome on Saturday.
The 26-year-old Team Movistar rider, who suffers from the rare blood condition haemophilia, improved the mark of 52.491km set by Australia's Rohan Dennis in February by 446 metres.
"The first 30 minutes were easier than I expected, the last 10 minutes were a bit grippy," said Dowsett. "I was expecting it to be horrific, but it was just terrible."
It is the fourth time the record has been broken since September 2014, and it may not stand for long.
Dowsett's fellow Briton Bradley Wiggins, the 2012 Tour de France winner and four-time Olympic gold-medallist, is scheduled to make an attempt on the record in London on June 7.
Dowsett hit the headlines in 2013 when he won one stage at the Giro d'Italia, as well as a third consecutive title at the British Time-trial Championships.
Despite being diagnosed with haemophilia, which impairs the body's ability to clot blood, he had dreamed of breaking the world hour record from an early age.
First set in 1893, the hour record has gained new credibility in the past year since world governing body the UCI laid down strict rules about the technology and position a rider is allowed to use.
"Alex has done an incredible job," said UCI president Brian Cookson on the organisation's website.
"This is great publicity for our event and for other riders who wish to follow in Alex's footsteps. Let's see what Bradley can do now."