In a built-up wheel having a hub and a wheel body which are connected with each other detachably by fastener means, the hub consists of a bearing cylinder and a wheel support member formed integrally with the bearing cylinder, while the wheel body is provided with a boss which is connected with the wheel support member by the fastener means, the boss being provided with an inner cylindrical portion formed integrally therewith so as to extend in the axial direction thereof for fitting engagement with the outer circumferential portion of the bearing cylinder. The hub and wheel body are formed of different kinds of synthetic resins. The modulus of tensile elasticity of the synthetic resin constituting the hub is set higher than that of the synthetic resin constituting the wheel body.