A wheel suspension system for a vehicle having a body supported on a set of wheels each provided with a rim and an axle generally consisting of a lower control arm pivotally connectable to a first portion of such body; an upper control arm pivotally connectable to a second portion of such body; a roller bearing having inner and outer races, disposed within such rim, coaxially relative to the rotational axis of the rim; a steering knuckle mounted on the outer race of the bearing, having a first portion pivotally connected to the lower control arm and a second portion pivotally connected to the upper control arm, defining a steering axis intersecting the rotational axis of the rim; and a hub member mounted on the inner race and connectable to an axle receivable through an opening provided in the steering knuckle.