Abstract: A wheel, preferably adaptable for use with a skate, is provided having a semi-permanent stiffness-modulating insert. The wheel comprises a toroidal wheel component having a hollow toroidal core which can be filled with a stiffness-modulating material. The wheel is split along a line from the inner circumference of the toroidal wheel component to the inner circumference of the core so as to allow for insertion of the stiffness-modulating material. The toroidal wheel component is preferably molded with the split edges slightly spaced apart from each other. In use the edges are held together in abutment with each other or with a toroidal spacer placed between them, preferably by wheel hubs engaging with each other and with the toroidal wheel component of the wheel.

Abstract: An improved wheel assembly which eliminates "bearing click" is provided with raised, deformable structures placed within a gap between a bearing and fixed structures inside the wheel core. When the bearing is pushed into the wheel to abut at least one such fixed structure, leaving a gap between the bearing and another fixed structure, then tightened mechanically inward into the wheel core, the deformable structure in the gap will be deformed by the bearing as it pushes inward and "cold flow" to form a surface preventing wobbling and "bearing click" when the user presses manually against the wheel hub.