GMA Engineering 2-Piston Custom Rear Brake Calipers Billet Aluminum Harley-Davidson 1973-2000

GMA Engineering 2-Piston Custom Rear Brake Calipers Billet Aluminum Harley-Davidson 1973-2000

Upgrade your vintage or classic Harley-Davidson’s rear brake system with stopping power that matches the rest of your build. GMA Engineering’s 2-piston rear calipers deliver the confident, progressive braking feel that old-style OEM cast units simply cannot match — giving you greater control, better modulation, and a look that belongs on a serious custom machine.

Key Features

• Precision machined from billet aluminum in classic fin or smooth body styles — a purposeful, clean aesthetic that pairs with any build direction
• Available in five finish options: Classic Clear Anodized, Classic Black Contrast, Classic Chrome, Smooth Black, and Smooth Chrome — availability varies by application
• Raw metal surfaces on Black Contrast calipers are anodized for a durable, long-lasting finish resistant to wear and corrosion
• Dual 1-5/8″ centerless ground pistons, hard anodized for extended service life and consistent performance
• Complete kit includes hanger brackets and brake pads — ready to install
• Manufactured in the U.S.A.

Technical Specifications

• Caliper Type: 2-piston
• Piston Diameter: 1-5/8″ centerless ground, hard anodized
• Body Styles: Classic Fin, Smooth
• Construction: Billet aluminum
• Compatible Rotor Size: 11.5″ (standard); 10″ for Big Twin Rigid Frame application
• Required Master Cylinder Bore: 5/8″
• Kit Contents: Caliper, hanger bracket, brake pads, brake line adapter fittings, axle spacers
• Country of Origin: Made in the U.S.A.

Fitment Notes

• Requires a 5/8″ bore master cylinder — old-style Wagner and Kelsey-Hayes die-cast aluminum OEM rear master cylinders use a 3/4″ bore and will not function correctly with these calipers
• Not recommended for use with imported stainless steel rotors
• Big Twin Rigid Frame application requires a 10″ rotor; all other applications use 11.5″ rotors unless otherwise noted
• Review the Fitment tab for the complete year and model breakdown specific to your application