Video: Gravity-powered karts look like a lot of fun

Clearly not every form of motorsport requires, well, a motor, as this gravity-powered race demonstrates. Filmed in Ecuador, it takes place on a serious-looking mountain road but obviously only in the one direction. The karts themselves are two-person affairs, a bit like toboggans with wheels, with the second rider acting as both propulsion during the start and on flatter, slower sections and as movable ballast, shifting their weight for stability in the corners.