GMA 100 Rear Brake Caliper Kit For Harley FL / FX 1973-1980
Modern Authority: GMA 100 Rear Brake Caliper Kit (1973–1980)
Give your vintage Big Twin the stopping power of a modern machine with the GMA 100 Rear Caliper Kit. For riders of 1970s FL and FX models, the original “banana” calipers are often a source of frustration due to their weight, clunkiness, and tendency to drag. GMA Engineering solves these issues with a high-performance, dual-piston billet aluminum solution that provides superior modulation and reliability.
High-Performance Billet Engineering
The GMA 100 series is built for riders who actually put miles on their classic iron:
Dual-Piston Opposed Design: Unlike the stock single-piston floating caliper, the GMA 100 uses two pistons that apply equal pressure to both sides of the rotor simultaneously. This results in a much more balanced “bite” and eliminates the uneven pad wear common in factory setups.
Billet Aluminum Rigidity: CNC-machined from aircraft-grade 6061-T6 billet aluminum, these calipers are incredibly rigid. This stiffness prevents the caliper from “spreading” under heavy pressure, ensuring that every ounce of force from your brake pedal is converted into deceleration.
Lightweight Efficiency: By removing the heavy cast-iron factory assembly and replacing it with billet aluminum, you significantly reduce unsprung weight, which improves the suspension’s ability to track road imperfections.
A Complete, Bolt-On System
Application-Specific Bracket: The GMA 100 kit is not a “universal” fit. It includes a dedicated mounting bracket designed to align perfectly with the 1973–1980 frame and 10-inch rear rotor.
Clean Aesthetics: Available in Classic Chrome or a Black Anodized finish, the GMA 100 has a low-profile, “Smooth” design that cleans up the rear wheel area while still looking at home on a vintage build.
Maintenance Friendly: GMA calipers utilize standard, readily available brake pads and seal kits, making long-term maintenance straightforward and affordable.
Technical Specifications
Fitment: Fits 1973–1980 Harley-Davidson FL and FX models (Shovelhead).
Rotor Compatibility: Designed for use with the 10-inch rear disc.
Hardware: Includes the caliper, mounting bracket, and high-friction brake pads.
Master Cylinder Note: Optimized for use with a 5/8″ or 3/4″ bore master cylinder.
Upgrade your classic ride with a braking system that works as good as it looks. The GMA 100 Kit is the most trusted name in vintage Harley performance braking.
GMA 100 Rear Brake Caliper Kit For Harley FL / FX
Features:
Big Twin Rear, 1973-80 Fits all 4-speed, square swing arms with 10″ rotor, from 1973-80
Hardware, machined aluminum bracket, fittings and axle spacer are included
Axle spacer fits between bracket counter-bore and swing arm
Kit requires 5/8″ bore master cylinder
| Product Style | AmericanV-twin Item # | Catalog Number | Store Sku | MFR. Product # | Availability |
|---|---|---|---|---|---|
| Black / Smooth | 10248594 | 243-538 | GMA-100SB | In Stock: Ships within 24 hours | |
| Black / Classic | 10248597 | 243-536 | GMA-100B | In Stock: Ships within 24 hours | |
| Chrome / Smooth | 10248595 | 243-539 | GMA-100SC/GMA100SC | Only 5 Left: Ships within 24 hours | |
| Chrome / Classic | 10248596 | 243-537 | GMA-100C | In Stock: Ships within 24 hours | |
| Clear Anodized / Classic | 10248589 | 243-535 | GMA-100/GMA100 | In Stock: Ships within 24 hours |
This Product Fits
Harley Davidson
Electra Glide Classic FLHC 1979, 1980
Electra Glide Sport FLHS 1977, 1978, 1979, 1980
Fat Bob FXEF 1979, 1980
FLH 1973-1980
Low Rider FXS 1977, 1978, 1979, 1980
Sturgis FXB 1980
Super Glide FX 1973-1979
Super Glide FXE 1974-1980
Tour Glide Classic FLTC/I 1979, 1980
Tour Glide FLT 1979, 1980
Wide Glide FXWG 1980
