Abstract: The coaster includes a wheeled foot platform, the steerable wheel of which is rotatable on a swiveled axle for effecting a steering action. The swiveled axle extends through aligned horizontal slots in vertical axle guides where are spherically curved. Each axle guide has at least one axially extending flange on which rides a bearing element or roller assembled on the axle. The roller and another bearing element assembled on the axle have complementary curved surfaces in sliding bearing engagement with opposite curved sides of each guide for axially constrained swiveled or turning movement of the axle. Steering of the coaster is obtained by a foot steerable plate mounted for pivotal movement on the foot platform. A mechanical linkage is connected at one end by a sliding pivot to the plate and at its other end to one or both ends of the swiveled axle.