A portable wheel assembly for use with bicycles and other wheeled vehicles. The wheel assembly comprises a centrally positioned hub which is adapted for rotatable movement about an axis. A plurality of pie shaped disk segments are coupled together along their radial side edges to form a circular support disk with a central opening. Each disk segment is adapted to removably couple with the hub at its innermost radial edge and extends radially outwardly to form a portion of a circular rim at its outermost radial edge. The rim is adapted for supporting a tire. The tire comprises a non-pneumatic tire with an annular ridge which is adapted to couple with the circular rim formed by the disk. During assembly, each of the pie shaped disk segments is coupled together and then coupled to the hub assembly at the inside radial edge or central opening. As the disk segments are coupled to the hub, the tire is assembled onto the outer radial edge or rim. Securing the supporting disk structure to the hub also secures the tire to the rim.