Guy visits the USA, where he hopes to win at one of America's oldest races: the Pike's Peak International Hill Climb.
In this annual contest, known as The Race to the Clouds, riders compete against the clock on a gruelling mountainside track that finishes over 4000 metres above sea level.
To learn the unique skills required in hill climb racing, Guy heads to the birthplace of the sport: Shelsley Walsh hill climb in Worcestershire. Racing up the course in an F1-style car, he realises that sheer horsepower and driving precision are vital.
However, in the thin air of Pike's Peak, Guy's body and bike will be desperately short of oxygen, which could seriously affect his performance. As well as trying to add more power to his homemade bike, Guy takes a high-altitude fitness test in a hypoxic chamber.
He soon realises how much harder his body will have to work and how the high altitude will affect his brain and cognitive performance; crucial when he has to remember the 150-plus bends in the road and avoid driving over a cliff!
After six months' preparation and a two-day road trip across America, Guy's success depends not just on how well he's tuned his bike and body, but on his own abilities as a racer
