A cyclist will help combat cystic fibrosis when he embarks on a gruelling 3,000 km ride from Vancouver to San Diego.

Will King, 32, a mining analyst from Colliers Wood, expects to spend seven weeks in the saddle as a tribute to a childhood friend who had cystic fibrosis and died waiting for a double lung transplant.

Milly Douglas-Pennant, 29, from Dorset, left behind a husband and 17-month-old daughter in 2010.

Mr King said: "Milly had cystic fibrosis but as a kid you don't really know what that means, but as I got older I saw she was often off to hospital.

"Her approach to life was very different to everyone else because she was conscious she was never going to live as long as everyone else."

Cycling between 80 and 100 km a day, he hopes the trip will raise awareness of the need for donor organs as well as raising funds for the Cystic Fibrosis Trust.

Mr King, who was drinking in the pub when he came up with the idea for the trip, will fly to Canada on April 7 and begin the challenge on April 14.

Travelling alone, he will carry everything he needs on his back.

He said: "It's about giving money and the gift of life."

Cystic fibrosis is a life-shortening genetic condition which causes internal organs to become clogged with mucus, resulting in chronic infections and inflammation of the lungs.

Directly affecting around 10,000 people in the UK, only half of sufferers live to celebrate their 40th birthday.

To sponsor Mr King, visit http://www.justgiving.com/willgoeswanderingcf