Fitment questions?
Call (855) 786-7101 or text (801) 304-3141.
Real people. Real answers.
Product details
This polished left-front GP310 is a direct fork-leg caliper for the Harley-Davidson applications documented in Wilwood’s 1984–1999 range. It uses four stainless pistons with 1.25-inch bores. The polished surface is the finish option; its left-hand mounting and rotor dimensions remain essential to the working fit. 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: 120-7737-P
- Caliper type: GP310 Motorcycle Front (1984-1999)
- Construction: Billet Aluminium
- Finish: Polish
- 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
Match the 3.44-inch mounting centers and 2.33-inch mount height to the correct fork. Check the rotor friction track, thickness and diameter before approving pad alignment. Springer and four-speed FL models are outside the stated application, and aftermarket forks or wheels require their own clearance verification. Wilwood also specifically includes the 1983 Harley-Davidson XR1000 front application; verify the same fork, rotor and mounting requirements.
PMB Performance brings over 20 years of brake and parts experience to selection questions. Send the existing caliper reference and brake-package details for help checking compatibility.
Brake-pad warning: Cancer and Reproductive Harm. www.P65Warnings.ca.gov. This warning applies to the brake pads.
