Lewis Flat Mount Road Bike Caliper Adapter

Lewis FM-F Adapter – Flat Mount to Flat Mount

Precision-machined flat mount brake adapter for lightweight strength, exact fitment, and flexible rotor sizing.

The Lewis FM-F Adapter is designed for riders and builders who want a clean, reliable way to fine-tune a flat mount disc brake setup. Machined from premium 7075-T6 aluminum using integrated CNC cutting, this adapter delivers excellent stiffness, precise alignment, and minimal added weight. At just 10 g, it is an ideal choice for performance-focused road, gravel, and lightweight build applications where strength and weight both matter.

Built primarily for front fork flat mount applications, the Lewis FM-F adapter gives you the flexibility to maintain your current rotor size or step up to a larger rotor for added braking power and improved heat control. Whether you are optimizing lever feel, increasing stopping authority, or dialing in a custom brake setup, this adapter helps you achieve a more refined and confidence-inspiring braking system.

FM-F Options

• FM-F Ф+0: Standard flat mount adapter configuration. Rotor diameter remains unchanged.
• FM-F Ф+20: Increases supported rotor size by 20 mm. For example, a fork designed around a 140 mm rotor can be adapted to run a 160 mm rotor.

Features & Benefits

• 7075-T6 Aluminum Construction: High-strength alloy provides excellent durability and stiffness while keeping weight extremely low.
• Precision CNC Machining: Integrated CNC cutting helps ensure a clean finish, accurate tolerances, and a precise fit for dependable brake alignment.
• Lightweight 10 g Design: Adds minimal weight to the bike, making it ideal for premium road, gravel, and race-oriented builds.
• Flat Mount to Flat Mount Compatibility: Designed to work within flat mount brake systems for clean integration and proper caliper positioning.
• Rotor Size Flexibility: Available in Ф+0 and Ф+20 options so you can match your setup to your braking needs.
• Improved Braking Setup Control: Makes it easier to optimize rotor sizing for better heat management, stronger braking performance, or specific frame and fork requirements.
• Performance-Focused Application: Well suited for riders building lightweight, responsive, and race-ready braking systems.

Why Rotor Size Matters

Choosing the correct flat mount brake adapter can directly affect braking feel and performance. Running a larger rotor can improve leverage, increase stopping power, and help manage heat more effectively on long descents or under repeated hard braking. The Lewis FM-F adapter gives riders and mechanics a simple way to adapt rotor sizing while maintaining a clean, high-performance flat mount setup.

Specifications

• Product Name: Lewis FM-F Adapter
• Adapter Type: Flat Mount to Flat Mount
• Material: 7075-T6 Aluminum
• Manufacturing Process: Integrated CNC Cutting
• Mounting Seat: 70 mm (FM-F specification)
• Fitment Note: Typically used for front forks
• Available Specifications: Ф+0 and Ф+20
• Weight: 10 g
• Colors: Black, Gunsmoke, Purple, Orange, Gold, Pink
• Application: Road, gravel, and performance bikes

Ideal For

The Lewis FM-F Flat Mount Adapter is ideal for riders, mechanics, and bike builders looking for a lightweight flat mount brake adapter that offers precise fitment, premium construction, and flexible rotor sizing options. It is especially well suited for road bikes, gravel bikes, and high-performance builds where clean integration and dependable braking setup matter.