Wilwood Engineering's new Starlite 55-XD Wide 5 racing hubs elevate performance and versatility for racing applications that require uncompromised strength, without excessive additional weight. At just over 7 pounds, the 55-XD achieves its 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 mounting plate that adds overall strength by eliminating the brake torque loading from the main hub body. For heavier vehicles, vehicles running high speeds on high-banked tracks, or vehicles that run on uncommonly rough tracks, 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, and a measurable increase in durability.
The rotor mount plates are configured for both fixed and dynamic rotor mounting by simply changing the bolt kits. With dynamic mount T-nut rotor bolt kits, stresses from the dissimilar thermal expansion rates of the iron rotor and the aluminum mount are fully isolated from the hub body and the rotor mount plate as well. For less extreme temperature applications, the rotors can be fixed mounted. But regardless of the mounting method, those stresses are now absorbed by the rotor plate, further reducing stresses and adding durability to the main hub body. All 55-XD hubs feature Wilwood's black E-coat finish to seal the castings and preserve its good looks. Rotor mounting plates and the bolts to attach the plate to the hub are included with all hubs. Front hubs include Snap Cap dust covers, while rear-drive flanges use bolt-on dust caps to use a rear hub in a front location, and all rotor bolt kits must be ordered separately.
Rear Hub, Rotor Mount Plate, 5/8-inch Course Studs -- PN 270-12111C