Wilwood 120-7737-BK GP310 Front Brake Caliper for 84-99 Harley-Davidson

Vehicle Fitment

• 1984-1999 Harley-Davidson Touring Models (FL, FLH, FLHT, FLHR, 1340cc/1450cc V-Twin)
• 1984-1999 Harley-Davidson Softail Models (FXST, FLST, 1340cc/1450cc V-Twin)
• 1991-1999 Harley-Davidson Dyna Models (FXD, FXDL, FXDWG, 1340cc/1450cc V-Twin)
• 1983 Harley-Davidson XR1000 (1000cc V-Twin)

Exclusions: Does not fit Springer front ends or 4-speed FL models. Fitment confirmed through 1999 production motorcycles where compatible mounting dimensions are used. Later models require different caliper configurations.

Features

• High-performance Wilwood GP310 4-piston motorcycle brake caliper
• Direct leg-mount design for compatible Harley-Davidson forks
• Lightweight billet aluminum construction for strength and reduced unsprung weight
• Four stainless steel pistons for improved braking force and corrosion resistance
• High-temperature piston seals for consistent braking under extreme conditions
• Black powder-coat finish for durability and corrosion protection
• Includes high-performance brake pads with stainless-rotor compatible compound
• Anti-rattle pad retention system for quiet and stable braking

Specifications

• Caliper Series: GP310
• Part Number: 120-7737-BK
• Position: Front Left
• Caliper Type: Fixed 4-piston
• Piston Diameter: 1.25 in (31.8 mm)
• Total Piston Area: 2.46 in²
• Rotor Diameter Range: 11.0-11.5 in
• Rotor Thickness: 0.25 in (6.4 mm)
• Minimum Rotor Thickness: 0.18 in
• Mount Type: Lug Mount
• Mount Center Spacing: 3.44 in
• Inlet Thread Size: 3/8-24
• Caliper Material: Billet Aluminum
• Finish: Black Powder Coat

Included Components

• 1x Wilwood GP310 Front Left Brake Caliper (Black)
• 1x Set High-Performance Brake Pads
• 1x Pad Retention Hardware Kit

Product Description

The Wilwood GP310 Front Brake Caliper (Part No. 120-7737-BK) is a high-performance upgrade designed specifically for compatible 1984-1999 Harley-Davidson motorcycles. Built from precision-machined billet aluminum, this caliper delivers exceptional strength while keeping weight low, improving both braking response and handling. Its four-piston configuration distributes clamping force evenly across the brake pads for stronger and more consistent braking performance.

This caliper uses stainless steel pistons and high-temperature seals to resist corrosion and maintain braking performance during demanding riding conditions. The GP310 design also incorporates a pad anti-rattle system and performance pad compound optimized for stainless steel rotors, providing reliable stopping power across a wide temperature range.

Designed as a direct leg-mount solution, the GP310 caliper offers a clean bolt-on installation for many Harley-Davidson models equipped with compatible mounting dimensions. Its durable black powder-coat finish provides a sleek custom appearance while protecting the caliper from road debris and corrosion, making it an ideal upgrade for riders seeking both performance and style.