Nick Skinner, 63, will set off from Land’s End, aiming to finish the 1,000-mile journey to John O’Groats in just over two weeks.
Mr Skinner said: “I’m really excited to take on the challenge, but I’m also a little daunted by it.
“I want to make it at least half way – which is to Cumbria.
“But I hope by then I will be in the rhythm and I’ll be able to continue through Scotland.”
The former BBC producer has set a fundraising target of at least £1,000 to support Emmaus South Wales and Epilepsy Action.
Emmaus South Wales supports people experiencing homelessness by offering work experience and training in its Bridgend-based community and charity shops.
Mr Skinner said: “I did a free video for them earlier this year, and I was blown away by the impact they had on the people they help.
“I thought that if I am going to cycle 1,000 miles, I might as well try to make some money for them.”
He is also raising funds for Epilepsy Action, a charity that promotes awareness and provides support for people living with epilepsy.
Mr Skinner, who has lived with epilepsy since childhood, said: “Like most people with epilepsy my seizures have been controlled with drugs.
“But until an effective treatment came along when I was 18 it did make life difficult.
“At times I used to have several minor seizures a day, which was really difficult when I was a teenager growing up.
“I wish there had been an organisation like Epilepsy Action to give me help and advice back then.”
Donations can be made at gvwhl.com/T2MDU.
