Abstract: The invention provides a heavy duty rim assembly (10) for use with a moulded or cast non-inflatable tyre, a wheel (100) including such a rim assembly and tyre (102), a mould (200) for such a tyre, and a method of manufacturing such a wheel. The rim assembly includes a nave (12) for mounting on a vehicle axle, a hollow barrel (14) around the nave, and a plurality of key members (16) around the barrel. The key members, in use, provide for effective bonding and keying of the rim assembly with the non-inflatable tyre. The key members define a belt (46) around the barrel, the belt being at least substantially concentric with and spaced apart from the barrel. The key members define holes (36) therethrough for tyre material to extend through in a completed wheel.