Patent ID: 7125083

Claim:
A method for constructing a wheel for coupling to a bearing ring, the method comprising: providing a polyurethane material prepared to be cured to a thermoset condition, the material when thermoset having a measurable hardness; providing a first mold for molding an inner wheel portion; filling the inner wheel mold with the polyurethane material; producing gas bubbles in the polyurethane material in the inner wheel mold; releasing the inner wheel portion from the mold; providing a second mold for molding an outer wheel portion; inserting the inner wheel portion in the outer wheel mold; filling the outer wheel mold with the polyurethane material to create the outer wheel portion and to bond the wheel portions together; releasing the bonded inner and outer wheel portions from the outer wheel mold, wherein the step of producing gas bubbles in the inner wheel portion includes adding hollow plastic spheres to the polyurethane material contemporaneously with filling the inner wheel mold with the material.