Caster

A lightweight caster is described that is resistant to ingress of debris into a caster bearing. The caster has a monolithic fork having an annular wheel-supporting portion and a chair-supporting portion. The wheel-supporting portion has a pass-through aperture for receiving a retainer. A rotational bearing is supported on the wheel-supporting portion, which supports a wheel rim such that the wheel rotates in the vertical plane. The rim has a pass-through aperture aligned with the pass-through aperture of the fork, and a ring at an inside edge of the bearing to retain the bearing between the rim and the fork and to inhibit debris from contacting the bearing. A retainer retains the rim on the fork and has an aperture aligned with the fork pass-through aperture. The retainer also has a bearing-retaining portion at an outside edge of the bearing to retain the bearing and to inhibit debris from migrating inwardly.