Abstract: An axle assembly for use with a portable radial stacker. The assembly includes a transverse member which is secured to the end of the supporting structure of the stacker proximate the ground and the member is aligned transversely to the direction of the conveyor belt. An axle bar is secured between two pairs of tires and two torsion levers complete the assembly. One end of each torsion lever is secured to the central part of the axle bar between each pair of tires and the opposite end of each torsion lever pivotally connects one end of the transverse member. Each tire has an independent suspension mounting and at least one drive means is provided for driving at least one pair of said tires.