Front Brake Master Cylinder Cover For Triumph Bonneville / T100 / T120 / Speedmaster

Front Brake Master Cylinder Cover for Triumph Bonneville, T100, T120, Bobber, Speedmaster

The front brake master cylinder reservoir on the Triumph Bonneville family sits visibly on the right-hand handlebar. On the stock configuration, the reservoir uses a plain plastic cap that adds nothing to the visual character of the bike. This front brake reservoir cover is a replacement cap machined from aluminum that replaces the stock unit, finishing the top of the reservoir with a clean, anodized surface that suits the Bonneville's design language — whether your build is stock, café racer, or custom.

The cover is CNC-machined from 6061 aluminum and available in five anodized finishes: Black, Dark Grey, Lavender, Gold, and Silver. Each finish is hard-anodized for corrosion resistance and durability under weather exposure. The cover threads into the reservoir opening using the same thread pitch as the original cap, making the swap direct with no modification to the reservoir body. An O-ring seal is included to maintain the reservoir seal. Installation takes under five minutes with basic hand tools.

At $39.90, this is one of the most cost-effective visual upgrades for the Bonneville platform. It sits at eye level on the handlebars and draws immediate attention from detail-oriented observers. Reviews from verified buyers highlight the quality of the anodizing and precise fit, with specific mentions of clean fitment on the T120 and Speedmaster.

Confirmed fitment for the Triumph Bonneville Bobber, T100, T120, Speedmaster, Street Scrambler, and Thruxton variants that use the same front brake master cylinder specification. Verify your reservoir thread spec before ordering if your bike has been modified with aftermarket brake components.

Frequently Asked Questions

Does it include an O-ring seal?

Yes. The brake reservoir cover ships with an O-ring sized for the standard Bonneville reservoir opening. The original plastic cap uses a diaphragm to handle fluid expansion; this aluminum cover uses an O-ring seal instead. Ensure the reservoir is properly full before fitting, and check the seal for leaks after the first ride.

Which color suits the Bonneville Bobber best?

The Bobber's palette tends toward black, dark finishes, and chrome accents. Black and Dark Grey anodized versions sit cleanly within that visual system. Gold and Silver work well on café racer and Scrambler builds where contrast is part of the aesthetic. Lavender is an unusual choice suited to custom builds with matching accent colors.

Free shipping on every order in the US. Every part is covered by a 1-year warranty and can be returned within 30 days of receipt.