Imagine cycling more than 2,200 miles in 34 days, a total of 306 hours at an average of 45 miles per day, breaking only for snacks.

That is the mammoth challenge facing Watford man John Ayers, who is looking to raise nearly £35,000 for children's cancer charity CLIC Sargent.

The 29-year-old, who works with people with spinal injuries, will cycle solo on the 3,500 kilometre ride, dressed from head-to-toe in the charity's colours - bright pink.

John, of Haines Way, Leavesden, said: “Most people think I must be mad. I looked at some group bike rides but you have to pay for them to organise it and I thought, why not just go and do it myself?

“In true British fashion I will be out to embarrass myself as much as possible. Starting by dying my hair bright pink.”

John's bike will also be sprayed and he will don a pair of bright pink lycra tights to ensure he stands out on the 3,500 kilometre journey - on which he will travel at an average 14 miles per hour for nine hours every day.

While he was travelling last year, John met a 60-year-old man cycling around the world on his bike – something he says inspired him to undertake this challenge.

“I've always been a keen rider I suppose but this guy was just amazing. I am a little nervous about the trip but I love meeting new people and this is exactly what I will be doing.”

As well as staying with friends and in his travel tent, John used social networking site couchsurfing.com to arrange accommodation on his trip.

The route will take him up to John O'Groats, across Scotland into Wales, down through Cornwall to Land's End and along the coast back towards London.

The journey begins on Sunday, September 5, and John is hoping donations will come flooding in once he is under way – his total so far is £161.

He said: “I hope that when people become aware of my trip they will be keen to donate. It is a fantastic charity that really moved me when I read into it. It is going to be hard work but I would like to think I would do everything possible to achieve my goal.”

CLIC Sargent is a charity that cares for children at all stages of cancer, either in hospital or at home.

To sponsor John on his bike ride, visit www.virginmoneygiving.com/psychojohnrides