US Patent 7891680 Flexboard for scooter rear end

A flexible riding board may include a front fork assembly for pivotal rotation about a front axis, the front fork assembly including a single front wheel mounted for rolling rotation about a front axle offset from the front axis; a rear fork assembly for pivotal rotation about a rear axis including a single rear wheel mounted for rolling rotation about a rear axle offset from the rear axis; and a flexible, one piece molded plastic platform having a neutral plane and supported by the front fork assembly with the front axis at a first acute angle to the neutral plane and supported by the rear fork assembly with the rear axis at a second acute angle to the neutral plane, the platform twistable by a rider to pivot the rear wheel about the rear axis so that the riding board is propelled in a forward direction, wherein the front fork assembly is pivotable about the front axis by the rider to steer the riding board.