Fitment questions?
Call (855) 786-7101 or text (801) 304-3141. We check fitment by VIN.
Product details
The chrome left-rear GP310 is the caliper identified by Wilwood for its Dyna bottom-bracket arrangement. It uses four 1.25-inch stainless pistons and a 3.50-inch mounting pattern. The left-hand body should be paired with the specified rear bracket rather than assigned the broader fitment of every GP310 rear installation. Based in Camarillo, California, Wilwood Engineering was founded by Bill Wood in 1977. The manufacturer produces disc brake systems and components for motorsport, street-performance and specialized applications, with a range covering calipers, brake rotors, master cylinders, valves, fittings and brake lines. Individual components are chosen to suit the complete brake system.
Technical Details
- Manufacturer part number: 120-7741
- Caliper type: GP310 Motorcycle Rear
- 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: 9.00–11.50 inches
- Mounting style: Lug
- Mounting side: Left 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
FL186 identifies the left-hand rear caliper for the Dyna bottom bracket and lists the separate 1984–1999 bracket application. Confirm the actual bracket reference on the motorcycle, rotor offset and pad track. The caliper is supplied without that bracket; check line routing and clearance at the lower rotor position before assembly.
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.
