20 - REAR WHEEL SPOILER The rear wheel spoiler does have an actual and beneficial reason for being there, it produces "down force" as the bike is thrown sideways, it gives resistance to the air flow and pushes the rear wheel into the shale, just like the rear wing on a car, therefore giving more drive and higher speeds in the corner. It also stops you getting your fingers in the spokes in the event of a crash! just like Barry Briggs did in 1972, losing a finger. (information courtesy of Kevin Lyth) The cover is also used by rider to advertise their sponsors.