US Patent 7650818 Bicycle shaft component

A bicycle shaft component includes an outer tubular member and an inner member non-movably attached to the outer member. The outer tubular member includes a first end portion and a second end portion with an interior longitudinal passageway extending between the first and second end portions. The interior longitudinal passageway has a longitudinal center axis extending through it. The inner member is non-movably attached to the outer tubular member within the interior longitudinal passageway. The outer tubular member is constructed of a first material having a first specific gravity and the inner member is constructed of a second material having a second specific gravity that is lower than the first specific gravity of the first material.