Brembo RMC Thumb Master Cylinder

RMC Thumb Master Cylinder
Master of Cornering

The Brembo RMC thumb master cylinder represents the technological pinnacle of ergonomic brake actuation in motorcycle motorsport. Developed directly from the demanding requirements of international top-tier racing series such as MotoGP and WorldSBK, this advanced performance component allows for highly precise rear brake modulation via thumb pressure. This provides a decisive performance advantage, particularly in extreme right-hand corners and maximum lean angles where the traditional foot brake lever becomes mechanically unreachable, allowing for effective chassis stabilization.

Manufactured using a sophisticated CNC-milling process from a single block of high-tensile billet aluminum, the compact cylinder housing features an outstanding stiffness-to-weight ratio. This extreme structural rigidity ensures a completely lossless, linear transfer of manual force into hydraulic pressure, effectively eliminating pressure point migration under continuous, high-stress racing conditions.

Features
- Ergonomic Thumb Actuation: Enables highly sensitive rear brake modulation to adjust lines mid-corner, control wheelies during hard acceleration, and stabilize the chassis during critical braking phases.
- Precision-Milled Billet Aluminum: Maximum resistance to structural deflection for crystal-clear, consistent lever feedback under extreme thermal and mechanical loads in the paddock and workshop environment.
- Flexible Mounting Architecture: The compact design allows for seamless integration on the left handlebar tube directly beneath the clutch assembly. The housing is specifically optimized to complement professional handlebar switches and data logging components.
- Wear-Resistant Hard-Anodized Finish: The specialized hard-anodization provides permanent protection against mechanical abrasion, extreme heat exposure, and aggressive contact with hydraulic brake fluids.

Technical Features
Material: Billet aluminium
Ø Piston: 14 mm
Lever ratio: 16 mm
Surface protection: Hard anodized
Handlebar fixing: Additional clamp
Brembo Part number: X985780
Weight: 175 g

Q&A
What are the main benefits of a billet-machined rear master cylinder?
The billet machining process enhances the mechanical strength, reduces weight, and improves overall precision and durability. It also ensures refined aesthetics, contributing to a high-quality braking experience and superior performance on the road or track.

Is a custom bracket required to install this master cylinder? 
Yes, this rear master cylinder requires a custom bracket for proper mounting, ensuring optimal positioning and functionality within your braking system.

Delivery Scope

Thumb Master Cylinder

Note

Delivery occurs without an external brake fluid reservoir, brackets, or accessory lines.
Clamp for attachment to the fork tube sold separately, see Accessories.

The Brembo Check app combined with the QR Code is another step in the fight against counterfeiting and will gradually replace the card. At this time both the new Brembo Check app and the anti-counterfeit card can be used to check that products are genuine.