The racing series that Isaac Newton would surely approve of: no engines, just gravity! Rival amateur teams descend on Mumbai to race their homemade soapboxes downhill.

Get ready for more thrills, spills, custom carts and crashes as Red Bull Soapbox returns for five brand-new races from across the world.

Teams of amateur racers once again design and build their own gravity-powered, engine-less soapbox vehicles and race them against the clock in an extreme downhill battle in front of thousands of fans

First, the Redbull Soapbox bandwagon rolls into Valkenburg aan de Gaul in the Netherlands (Saturday 23rd). Traditionally the leg-killing finish of the Amstel Gold Classic cycling race, Valkenburg's famous Cauberg hill swaps the uphill struggle for downhill fun.