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Product details
This chrome GP310 is a right-hand rear sprocket-brake caliper for a custom Harley-Davidson installation. Four 1.25-inch stainless pistons operate in a billet aluminum body designed around a nominal 0.35-inch braking surface. Bill Wood established Wilwood Engineering in 1977. Based in Camarillo, California, the company designs and manufactures disc brake systems, from calipers and brake rotors to master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized use.
Technical Details
- Manufacturer part number: 120-10174. Component: GP310 Motorcycle Rear (Sprocket Brake) caliper.
- Supply: one brake caliper, not a complete axle brake kit. Match the mating rotor, pads, bracket and connection hardware to the installation.
- Piston dust boots: not fitted.
- Nominal rotor width 0.35 inch; compatible outside diameter from 9.00 through 11.50 inches. Specified rotor-width limits: 0.29–0.35 inch.
- Pad fit is type 6208. Match the pad dimensions and compound to the rotor and intended braking conditions.
- Caliper weight: approximately 2.3 lb.
- Hydraulic inlet thread: 3/8-24. Use a fitting with the correct thread and sealing seat.
- Construction and surface: billet aluminum housing finished in Chrome.
- Bracket interface: 3.50-inch lug centers with 0.39-inch holes; orientation: right hand.
- Bore configuration 1.25 inches across 4 pistons; piston material: stainless steel. Hydraulic effective area: 2.46 square inches.
Fitment & Compatibility
Match the caliper to the specific sprocket-brake bracket and rotor arrangement. Its 3.50-inch lug spacing and 9.00–11.50-inch diameter envelope do not imply fitment to every motorcycle using a GP310-family brake.
With 20+ years of experience, PMB Performance can help compare the actual brake hardware. Supply the caliper number, rotor dimensions and mounting measurements when asking about compatibility.
