Abstract: An acrobatic amusement device comprising an outer wheel affixed to a stationary platform. The outer wheel has a track on its inner circumference and a riding unit is supported within the outer wheel for movement relative to this track. The riding unit comprises frame members having three rotatable wheels thereon which mate with the outer wheel track at two places on one side of a diameter of the outer wheel and at one place on the other side of that diameter. The riding unit can be given a motion relative to the track and rotary within the outer wheel about an axis coincident with the axis of that wheel to provide amusement and thrill for an occupant sitting upon the riding unit. A locking device may be provided to hold the riding unit in fixed relationship with respect to the outer wheel to allow the rider to mount and dismount from the riding unit, and a seat belt may be provided which must be fastened before the locking device will release.