At its heart a bike is a fairly simple engineering enterprise; a frame for support, two wheels for traction, direct drive gears and chain for power, and handlebars to steer. But when it comes to professional road racing, the complexity multiplies. Although injury has prevented Sir Bradley Wiggins defending his 2012 Tour de France crown when the race begins on 29 June, Team Sky will still field a strong squad including Chris Froome. The Kenyan-born cyclist, who rides for Great Britain, claimed a bronze in the individual time trial at the London Olympics last year. The highly engineered machines that Froome and his team mates will race over the 23 days, 3360 Km and 21 stages of Le Tour, are as far away from the road bikes that cycle the roads of the UK as a Formula One car is from a Ford Focus. Much like a Formula One car, a professional bike is the sum of all its parts; chassis, wheels, tyres and gears. The frames raced by Team Sky come from Italian manufacturer Pinarello; the Dodma 2 chassis for road racing and the Bolide for time trials.