Channel 4 - Speed with Guy Martin: Series 2 (2014)

Motorcycle racer and mechanic Guy Martin undertakes a series of speed-based challenges, exploring the boundaries of physics and learning about the science of speed Guy takes on four more speed-based challenges. From racing a motorbike at altitude to trying to break the speed record for a hovercraft, Guy wants to find out what makes things go fast.

Part 1: Tandem
The motorbike racer takes part in four more speed-based challenges and gets his hands dirty in unique engineering projects to discover what makes things go fast. In the first programme, he finds out how far it's possible to travel on a bicycle during 24 hours of non-stop pedalling. With the help of bike experts Miles Kingsbury and Mike Burrows he builds a tandem, and pairs up with his friend, endurance expert Jason Miles, to see how far they can push their bodies. In the build-up to the final record attempt at the historic Goodwood Motor Circuit, Guy also learns about the science of cooking for athletes with nutritionist Nigel Mitchell, who instructs him to lose five kilos and recommends a new diet regimen.

Part 2: Pikes Peak
Guy heads to Colorado, where he hopes to win one of America's oldest races - the Pikes 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 more than 13,000ft above sea level. To learn the skills required in hill-climb events, Guy visits the birthplace of the sport - Shelsley Walsh in Worcestershire. Racing up the course in an F1-style car, he realises sheer horsepower and driving precision are vital, but he must also take a high-altitude fitness test in a hypoxic chamber to prepare for the challenge ahead.

Part 3: Hovercraft
The motorcycle racer leaves his comfort zone as he attempts to set a world speed record for a hovercraft. These machines are notoriously difficult to control, so to learn the basic skills needed he's put through his paces by Royal Marines in a military training operation. To achieve his goal, Guy will need to stay over 86mph for a kilometre, but at these speeds, because of the hovercraft's inherent instability, even the most experienced pilots can lose control - and the worsening weather makes things that much more challenging.

Part 4: Gravity Racer
The motorbike fan takes on the challenge of building the world's fastest soapbox racer in an attempt to set a new speed record using just the pull of gravity and a tarmac road. To get to grips with going blisteringly fast on a public road, Guy tries his hand at street luge with former global champion Helene Schmit, before joining his team of engineers to explore the science of rolling resistance and the importance of tyre pressure. Armed with what they believe to be the perfect formula, they produce a unique soapbox cart inspired by Mother Nature and, after training with the Team GB women's bobsled pair, confidence is high - but are disaster and mayhem just around the corner?