Abstract: A loading bar is mounted on a leaf spring of a racing vehicle rear axle suspension system to increase traction on the vehicle tires during acceleration. Strut tube and strap members are mounted in a spaced relationship on the vehicle leaf spring rearwardly and adjacent to the vehicle axle by a pair of U-bolts and reinforcing plates. The tube and strap members extend rearwardly from the axle and are joined at their extended ends by a wheel bracket and a strut tube adjusting channel. The strut tube extends in an upwardly angled direction between the adjusting channel and axle, with the strap member being generally parallel with respect to the ground or racetrack. A wheel or roller is mounted on the wheel bracket and is spaced above the ground when in static condition. The loading bar is readily adjustable on the leaf spring to change the traction aiding effect thereof.