Mini R55 R56 R57 JCW John Cooper Works Rear Wheel TRW Brakes Caliper Set 280X10

Mini R55 R56 R57 JCW John Cooper Works Rear Wheel TRW Brakes Caliper Set is a factory-spec brake system component set designed for the rear axle of Mini R-series models in John Cooper Works versions. This solution is intended for users who expect consistent operation of calipers with discs and the maintenance of braking characteristics in accordance with the manufacturer's specifications.

Specifications and technical data

• SKU: 6784645/6784646
• Mark: Mini (Genuine OE)
• Condition: Used
• OEM Part Number: 6784645/6784646
• Substitutable numbers: 6784645, 34216784645, 6784646, 34216784646, 6784389, 34216784389
• Location on the vehicle: Rear
• Category: Brake Disc Rotors

Intended use and set configuration

The presented set includes the rear part of the Mini JCW brake system, based on 280x10 TRW discs and matching calipers. The set is configured for the specific R55/R56/R57 platform, which allows for maintaining the correct operating parameters of the system, including braking force stability and proper interaction with the vehicle's factory electronics.

The placement on the vehicle is the rear axle, making this set a perfect base for refreshing or restoring the efficiency of the rear brake section in Mini cars of this generation, without the need to mix different manufacturing standards.

Technical characteristics of the brake system

TRW brake discs with a diameter of 280 mm and a thickness of 10 mm belong to a popular configuration used in sporty Mini variants, providing an adequate friction surface for the calipers and predictable heat dissipation. Using a complete set with calipers reduces the risk of friction element mismatch, which is important for both braking efficiency and even wear of pads and discs.

The cooperation of the discs with dedicated calipers translates into:

• stable braking force distribution on the rear axle,
• consistent operation with the factory front/rear braking force distribution,
• maintenance of system operating characteristics in line with JCW version specifications.

Application in Mini models and benefits of installation

The set is intended for Mini cars from the R55, R56, and R57 family in John Cooper Works versions, where the brake system operates under higher loads than in standard variants. Using a set based on 280x10 TRW discs allows for maintaining proper thermal reserve and braking repeatability during dynamic driving.

The main advantages of installing this set include:

• preservation of factory geometry and mounting points on the rear axle,
• reduction of the risk of vibration and uneven disc runout thanks to matched components,
• easier diagnostics and service in the future due to the use of solutions compliant with the original Mini JCW configuration.

Condition of components and practical aspects

The set comes from the Brake discs category and is offered as a used item, which allows for an economical restoration of the rear brake section while maintaining the original specification. For many Mini users, this is a reasonable compromise between cost and maintaining the proper brake operating characteristics.

Before installation, it is recommended to perform a standard verification of the condition of the disc working surfaces and caliper guide elements, as well as to match the brake pads to the specific type of disc. Such an approach facilitates achieving a predictable effect after replacement and shortens the time of any potential service adjustments.

Brake system expansion and technical knowledge

If you are planning a comprehensive repair or upgrade of the brake zone in your Mini and need other elements from the same group, such as additional discs, pads, or brake lines, check the available parts in the Mini Brake discs category.

When selecting used brake system components – especially discs and calipers – it is worth relying on a proven procedure for assessing technical condition. Practical tips on how to safely choose such components can be found in the article Second-hand brake system: how to safely choose discs, calipers, and ABS?, which provides a useful supplement to your knowledge before purchasing this type of set.

If you want to learn more about the specifics of the second-hand parts market and make informed purchasing decisions, the material Used car parts: Myths and facts you need to know, which discusses the most common doubts related to components from dismantling, will also be helpful.