Absolute Authority: Performance Machine Rear Caliper Kit (1970–1984)

Bring your classic Shovelhead’s braking performance into the 21st century with the Performance Machine (PM) 4-Piston Rear Caliper Kit. For decades, owners of 1970s and early 80s FL and FX models have struggled with the “Banana” caliper’s tendency to drag, rattle, and provide “spongy” feedback. PM solves these vintage headaches with a high-pressure, opposed 4-piston system that delivers immediate, predictable deceleration every time you hit the pedal.
Engineered Performance for Classic Iron

This isn’t a universal adaptation; it is a specialized kit designed to interface perfectly with the Shovelhead chassis:

Superior 4-Piston Clamping: Moving from a single-piston floating design to a fixed 4-piston assembly provides a massive increase in pad-to-rotor contact. This ensures a firm, linear pedal feel and significantly shorter stopping distances, even when your bike is fully loaded for touring.

Billet Aluminum Rigidity: CNC-machined from a solid block of 6061-T6 aluminum, the PM caliper resists the “flex” and heat expansion found in factory cast-iron or cast-aluminum units. This rigidity is the key to maintaining a consistent “bite” during heavy use.

Integrated Mounting Bracket: The kit includes a dedicated, high-strength mounting bracket designed to align the caliper perfectly with your specific year and model’s swingarm and axle configuration.

Iconic Style and Modern Reliability

Sleek, Low-Profile Design: The PM 4-piston unit is significantly lighter and more compact than the original “banana” assembly, cleaning up the look of your rear wheel and showcasing more of your classic frame and spokes.

Signature PM Finishes: Available in show-quality Chrome, Contrast Cut (black with machined highlights), or a stealthy Black Ops finish to match your restoration or custom build.

Serviceability: Unlike obsolete vintage parts, this caliper uses standard, high-performance PM brake pads and modern internal seals that are readily available for future maintenance.

Technical Specifications

Fitment: Fits 1970–1984 Harley-Davidson FL and FX models (Big Twin).

Rotor Compatibility: Kits are available for both the early 10-inch and later 11.5-inch rear rotors.

Complete Kit: Includes the 4-piston caliper, application-specific mounting bracket, high-friction brake pads, and all necessary mounting hardware.

Axle Size: Designed to work with the standard 3/4″ rear axle common to this era.

Stop wrestling with outdated braking technology. The Performance Machine Rear Caliper Kit is the most trusted way to add safety, confidence, and world-class style to your classic Harley-Davidson.

This Product Fits

Harley Davidson
Disc Glide FXDG 1983
Electra Glide Classic FLHC 1979, 1980, 1981
Electra Glide Classic FLHTC/I 1983
Electra Glide Sport FLHS 1977
Electra Glide Standard FLHT/I 1983, 1984
Fat Bob FXEF 1979, 1980, 1981
FLH 1970-1984
Low Rider FXS 1977-1982
Sturgis FXB 1980, 1981, 1982
Super Glide FX 1971-1978
Super Glide FXE 1974-1984
Wide Glide FXWG 1980, 1981, 1982, 1983, 1984