Fitment questions?
Call (855) 786-7101 or text (801) 304-3141. We check fitment by VIN.
Product details
Black powder coating finishes the right-hand rear GP310 caliper. It uses a 3.50-inch bracket interface and four equal stainless pistons, giving the published 2.46-square-inch piston area. This is a caliper component for a matched Harley-Davidson rear package, with the application-specific bracket obtained separately. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. The company makes disc brake systems and components for motorsport, street-performance and specialized uses, including calipers, brake rotors, master cylinders, valves, fittings and brake lines; each component must match the requirements of the complete brake system.
Technical Details
- Manufacturer part number: 120-7740-BK
- Caliper type: GP310 Motorcycle Rear
- Construction: Billet Aluminium
- Finish: Black Powder Coat
- Piston bores: 1.25 / 1.25 inches
- Piston type: Stainless
- Piston count: 4
- Published piston area: 2.46 square inches
- Dust boots: No
- Nominal rotor width: 0.25 inch
- Rotor thickness limits: 0.18–0.25 inches
- Rotor diameter limits: 9.00–11.50 inches
- Mounting style: Lug
- Mounting side: Right Hand
- Mounting centers: 3.50 inches
- Mounting-hole size: 0.39 inch
- Mount height: 1.55 inch
- Hydraulic inlet thread: 3/8-24
- Required pad shape: 6208
- Published pad area: 3.65 square inches
- Published pad volume: 0.63 cubic inches
- Manufacturer-listed component weight: 2.1 lb
- Supplied brake components: Individual GP310 caliper with brake pads
Fitment & Compatibility
Check the existing conversion or bracket reference and the motorcycle’s rear rotor dimensions. The bracket establishes position and offset, so caliper mount spacing alone is insufficient. Confirm the hydraulic line and system fluid requirements, then inspect wheel, sprocket or belt clearance and ensure the bleed point is correctly positioned.
With over 20 years of parts experience, PMB Performance can help compare this component with your existing brake assembly. Include its caliper reference and any conversion-kit information.
Brake-pad warning: Cancer and Reproductive Harm. www.P65Warnings.ca.gov. This warning applies to the brake pads.
