The Wilwood Wide-5 XD Rear Hub with Dynamic Rotor Plate Mount elevate performance and versatility for racing applications that require uncompromised strength without excessive additional weight. At just over 7 pounds, the 55-XD achieves it superior strength and modest weight through a highly efficient redesign of racing’s most popular wide 5 hub, the Starlight 55. The 55-XD employs a bolt-on rotor mount plate that adds overall strength by eliminating the brake torque loading from the main hub body, by taking the stress loads of the braking torque out of the hub body and moving it to the thicker, stronger section of the hub near the inner wheel bearing, provides a measurable decrease in stress deflection in the body.