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Product details
The chrome left-front GP310 supplies a four-piston caliper for the supported 1984–1999 Harley-Davidson front brake. Its billet body mounts directly to the appropriate fork leg, with 3.44-inch centers and a 3/8-24 inlet. A left-hand configuration is required where the rotor and fork mounting call for this side. Bill Wood founded Wilwood Engineering in 1977; the company is based in Camarillo, California. Wilwood designs and manufactures disc brake systems and components, from calipers and brake rotors to master cylinders, valves, fittings and brake lines, for motorsport, street-performance and specialized applications; selection depends on the complete brake system.
Technical Details
- Manufacturer part number: 120-7737
- Caliper type: GP310 Motorcycle Front (1984-1999)
- Construction: Billet Aluminium
- Finish: Chrome
- 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: 11.00–11.50 inches
- Mounting style: Lug
- Mounting side: Left Hand
- Mounting centers: 3.44 inches
- Mount height: 2.33 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: 2.0 lb
- Supplied brake components: Individual GP310 caliper with brake pads
Fitment & Compatibility
Check the actual fork rather than using year alone, especially on modified motorcycles. Wilwood’s application excludes Springer and four-speed FL models. Match rotor thickness and diameter to the stated limits, confirm pad contact and wheel space, and retain the correct brake-line connection and system fluid requirements. Wilwood also specifically includes the 1983 Harley-Davidson XR1000 front application; verify the same fork, rotor and mounting requirements.
PMB Performance has over 20 years of experience helping customers with brake and parts fitment. Share the installed component identification and relevant measurements when requesting assistance.
Brake-pad warning: Cancer and Reproductive Harm. www.P65Warnings.ca.gov. This warning applies to the brake pads.
