GMA Engineering 5/8 Inch Bore Master Cylinder Brake Lever for 1-Inch Handlebars

GMA Engineering 5/8 Inch Bore Master Cylinder Brake Lever for 1-Inch Handlebars

Give your custom build the stopping confidence it deserves with a master cylinder assembly that delivers firm, consistent brake feel from the first pull. Whether you are finishing a long-term chopper build or refreshing a bobber’s hand controls, this American-made assembly delivers the clean, purposeful look and performance that serious builders count on.

Key Features

• 5/8-inch bore delivers firm, responsive braking feel suited for custom chopper and bobber applications
• CNC-machined construction with a clean, low-profile design purpose-built for custom builds
• Right-hand mounting orientation — direct fit for front brake lever position
• Complete assembly includes mounting clamps and lever — ready to install out of the box
• Available with or without an integrated switch kit to suit your build configuration
• Switch kit includes three momentary switches with buttons and dedicated switch housing
• Switch wiring supports internal or external routing for maximum handlebar layout flexibility
• Made in the U.S.A.

Technical Specifications

• Bore Size: 5/8 inch
• Handlebar Diameter: 1 inch (non-dimpled bars only)
• Mounting Side: Right hand (front brake)
• Brake Fitting Thread: 3/8″-24
• Brake Fluid Type: DOT 5
• Construction: CNC-machined aluminum
• Includes: Mounting clamps and lever
• Switch Kit Option: Available with or without switch kit
• Switch Count (kit variant): 3 momentary switches with buttons and switch housing
• Switch Wiring (kit variant): Internal or external routing
• Finish Options: Black, Chrome, Polished
• Country of Origin: USA

Fitment Notes

• Compatible with most 1-inch diameter handlebars; not compatible with dimpled bars
• Requires 3/8″-24 brake line fitting — verify your brake line thread spec before ordering
• Designed for use with DOT 5 brake fluid only — do not use DOT 3 or DOT 4
• Intended for custom and builder applications; confirm lever reach, clamp clearance, and brake line routing prior to installation
• Please review the Fitment tab for complete compatibility details