Molded-composite rear upright features built-in 0° of outboard toe to improve traction and prevent suspension geometry changes in serious crashes. This 1-hole upright may be used on high-traction tracks or tracks with long sweepers, since the position of the center hole will allow faster driving through those corners because of better cornering speed. More roll center positions can be easily adjusted by adding shims between the upright and the turnbuckle ball joint. The rear upright feature small but robust 5x10x4 ball-bearings to minimize unsprung weight.

Medium rigidity (labeled “M”) specially optimized for rubber-tire racing. For use on both left and right sides of the car. Can be also used for foam tires.