A one-piece tire has an elastomer material composition that is homogeneous and consistent throughout the entire tire. An annular outer portion of the one-piece tire includes an outwardly facing surface that defines an outer circumference of the tire and a width of the tire between a first edge on a first lateral side and second edge on a second lateral side of the tire. An annular inner portion defines an inner circumference of the tire. The annular inner portion has a first edge on the first lateral side of the tire and a second edge on the second lateral side of the tire. An annular resilient spring portion extends from a first junction near the first edge of the annular inner portion to a second junction near the second edge of the annular outer portion.

A wheel assembly may include an inner rim to be coupled to a hub of a vehicle, an outer rim surrounding the inner rim, and gas springs operatively coupled between the inner and outer rims to provide a gas suspension. The wheel assembly may also include tread assemblies carried by the outer rim. The wheel assembly may also include fastener assemblies. Each fastener assembly may couple respective adjacent wheel assembly components. Each fastener assembly may include a fastener, a lock washer having a sloped surface, and a slotted wedge including a frusto-conical body having a slot therein. The slotted wedge may have a sloped surface slidably engaging the lock washer sloped surface to permit relative rotation so that loosening from a fully tightened position exposes a gap therebetween.

A wheel assembly may include an inner rim to be coupled to a hub of a vehicle, an outer rim surrounding the inner rim, and a rigid cover ring coupled to the outer rim and extending radially inward toward the inner rim. The wheel assembly may also include gas springs operatively coupled between the inner and outer rims to provide a gas suspension for relative movement between the inner and outer rims. The wheel assembly may also include fastener assemblies, each coupling respective adjacent components and including a fastener, a lock washer carried by the fastener and having a sloped surface, and a slotted wedge carried by the fastener and including a frusto-conical body having a slot therein. The slotted wedge may have a sloped surface slidably engaging the sloped surface to permit relative rotation so that loosening from a fully tightened position exposes a gap therebetween.