A team will set off from Chorleywood on a 250-mile challenge riding a four-wheeled cycle.
The eight-day journey starts on Saturday, September 26, and ends in Dartmouth, Devon, via Reading, Dummer, Romsey, Christchurch, Osmington Mills, Lyme Regis and Exmouth.
Nicknamed The Quadfather, the gearless four-person cycle was restored over a year after being bought as a wreck for £1,000.
Dean Tanner, who is leading the challenge, said: "We’re definitely not athletes – there are seven of us in our 50s and three in our 60s – so this is going to be a challenge.
"The Quadfather is a heavy, gearless, four-wheeled cycle that was never designed for hills.
"We’ll be doing our best on the flat and downhill, and anything uphill may involve getting off and pushing."
The Woods to the Waves challenge aims to raise £40,000 for Keech Hospice and Brain Tumour Research.
The challenge was inspired by 12-year-old Betsy Griffin, who lost her sight after developing a brain tumour aged two.
Betsy suggested supporting the two charities.
Supporters can donate through the team’s fundraising page at https://givewheel.com/fundraising/14180/woods-to-the-waves/
Share