A wheel construction includes a wheel rim having axially inner and outer portions and a mid-portion, and each axially inner and outer portion, a connecting surface adjoining a flange and extending towards the mid portion. The construction includes a side part between the connecting surface and the mid portion, and for at least one of the inner and outer portions, the connecting surface is a frusto-conical having an axial end of greatest radius and an axial end of least radius, the connecting surface the greatest radius, adjoining the flange and the axial end of least radius adjoining a circumferentially extending convex surface which extends beyond the end of least radius, and a selected side part including a generally frusto-conical region and a curved region including circumferentially extending concave surfaces and the curved region adjoining the end of least radius.