Engineering Excellence: GMA Front Single Disc Caliper Kit (1973–1984 FL)

Modernize the braking response of your Shovelhead or early Evolution Electra Glide with the GMA Front Single Disc Caliper and Bracket Kit. For riders of vintage FL models, the original factory calipers are known for being heavy, prone to rattling, and delivering a “wooden” lever feel. GMA Engineering eliminates these issues with a high-performance, dual-piston billet aluminum system designed for riders who demand both safety and style.
High-Performance Billet Engineering

The GMA “A” series caliper is built with a focus on rigidity and hydraulic efficiency:

Dual-Piston Opposed Design: Unlike the original single-piston floating design, the GMA unit uses two pistons that apply equal pressure to both sides of the rotor simultaneously. This provides a more balanced “bite” and significantly more predictable modulation at the lever.

Billet Aluminum Rigidity: CNC-machined from aircraft-grade 6061-T6 billet aluminum, these calipers resist expansion and “flex” under heavy braking. This ensures that every bit of force from your master cylinder is converted into stopping power, eliminating the spongy feel common in vintage bikes.

Reduced Unsprung Weight: By replacing the heavy cast-iron or cast-aluminum factory assembly with lightweight billet aluminum, you improve front-end suspension tracking and overall handling.

A Complete, Direct-Fit Solution

Dedicated FL Mounting Bracket: This kit is engineered specifically for the wide-glide front ends of 1973–1984 FL models. The included bracket ensures perfect alignment over your factory 10-inch front rotor.

Clean, Low-Profile Aesthetics: Available in a Clear Anodized (Silver) or Black Anodized finish, the GMA caliper has a smooth, timeless design that cleans up the front of your bike while showcasing your spokes and chrome.

Serviceability: GMA calipers are engineered for longevity, utilizing high-grade internal seals and standard replacement brake pads that are easy to source for future maintenance.

Technical Specifications

Fitment: Fits 1973–1984 Harley-Davidson FL models with single disc front ends.

Rotor Compatibility: Designed for use with the factory 10-inch front disc.

Master Cylinder Note: Works best with the original 5/8″ or 3/4″ bore front master cylinders.

Made in the USA: Every GMA kit is engineered and manufactured domestically to ensure the highest quality standards.

Don’t let outdated braking technology hold your classic back. The GMA Front Caliper Kit is the professional’s choice for adding confidence-inspiring performance to vintage Harley-Davidson touring models.

Fitment Notes & Exceptions

Will not fit models with dished brake rotors
Kit requires 5/8″ bore master cylinder

This Product Fits

Harley Davidson
Electra Glide Classic FLHC 1979, 1980, 1981, 1982
Electra Glide Classic FLHTC/I 1983, 1984
Electra Glide Special FLHX 1984
Electra Glide Sport FLHS 1977-1984
Electra Glide Standard FLHT/I 1983, 1984
FLH 1973-1984
Tour Glide Classic FLTC/I 1979-1984
Tour Glide FLT 1979-1984

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

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