Double Olympic gold medallist rower James Cracknell is saddling up a retro Raleigh Chopper to raise money for Sport Relief 2016.
Cracknell will take part in a challenge dubbed The Great Sport Relief Bike Off, where he will try to cycle the furthest distance ever ridden on a classic 1970s Chopper bicycle in one hour.
At the same time, a team of cyclists and celebrities including Sally Gunnell, Alastair Campbell and Mike Bushell will attempt to break the Guinness World Record for the most people to cycle a 1km time-trial in 60 minutes.
Both challenges will take place in front of a live audience at Queen Elizabeth Olympic Park, east London, on Friday and will be broadcast on BBC One.
However, the results of their efforts will not be revealed until the Sport Relief Games Show at 1.15pm on BBC One on March 20.
Cracknell said: “It’s going to require a lot of pedal power, but I’m excited to push myself to the limit and set a new Sport Relief record on my trusty Chopper.
“I feel hugely proud to support such an amazing charity and hopefully inspire people to take on their own challenges in the Sport Relief Games. Get fit, have fun and raise much‐needed cash to transform lives here in the UK and around the world.”