A wheel suspension system 10 is disclosed which includes a wheel support member 14 pivotally mounted to a vehicle frame 12, a wheel 11 rotatably mounted to the support member 14 on a stub axle 16, and an airbag 18 positioned between the wheel support member 14 and the vehicle frame 12 to bias the support member 14 into an intermediate position between a lowermost position and an uppermost position, the rotational axis 17 of the wheel 11 being positioned at or above the cargo floor 26 of the vehicle at least when the wheel support member 14 is in the uppermost position. The suspension system 10 aligns the pivot point 33, wheel mount 16, and airbag 18 to provide a compact lateral profile, thus providing maximum distance between the wheels 11 and permitting the cargo floor 26 to be supported between the wheels 11, and in some instances below the rotational axis 17 of the wheels 11. The wheel support members 14 are typically mounted in one, two or three pairs on opposite sides of the vehicle, either as the exclusive wheels 11 on a trailer, or as the rear wheels 11 of a front wheel drive van or similar vehicle.