A releasable clamp system for clamping an axle of a wheel to a two wheeled vehicle comprising a frame member and a cover plate that is pivotally coupled to the frame member. The cover plate is movable between a closed portion where the cover plate and the frame member encompass the wheel axle and an open position that permits removal of the wheel axle. A lever is pivotally attached to the cover plate and a hook, member is pivotally attached to the lever. An adjustment system is used to adjust the clamping force applied to the axle by the frame member and the cover plate.