Two school friends are raising money for Northamptonshire Air Ambulance by cycling across South America on an 8,000-mile journey.
James, from Cold Ashby, and pal Roo will set off on January 24 to cover the length of the continent from Ushuaia at the southern tip of Argentina to Cartagena in Colombia.
The 8,000-mile route crosses six countries and is in aid of four charities close to James and Roo, who met at boarding school in Rutland.
The pair's journey will be unsupported, meaning they'll have to carry their own clothes, tent and other gear with them at all times in bags attached to their bikes.
"The reason we chose South America is because it's an amazing continent to do something like this in," said James.
"It's a huge challenge and we hope we can finish it in four months."
With temperatures likely to range from 25C in Colombia to -10C in Patagonia, the pair's progress will be affected by the weather conditions.
The 23-year-olds will camp every night and will ride an average of 75 miles every day.
Training for Roo and James, who both work in London, has consisted of daily and sometimes twice daily spin, yoga and pilates classes.
"We haven't booked our return flights yet but we're aiming to be home by May 18," said James.
"My sister is due to give birth on the 12th so that's an incentive for me."
The aim for the school friends is to raise £30,000 for their chosen charities: the Charlie Watkins Foundation, Northamptonshire and Warwickshire Air Ambulance, War Child and Sands.
James says he has always wanted to raise money for the air ambulance because on two occasions, in 2008 and in 2010, their crew flew out to help his grandmother.
In the first instance, they came to her rescue after she had fallen off her horse; the second time was more tragic when she suffered fatal injuries in a farming accident.
James and Roo hope to raise an initial £15,000 and a further £15,000 at a charity dinner when they return home.