Precision and Power: Performance Machine 4-Piston Rear Caliper Kit

Upgrade your Softail’s rear braking from “adequate” to “elite.” The Performance Machine (PM) 4-Piston Differential-Bore Rear Caliper is engineered specifically for the unique requirements of the 2008–2017 Softail swingarm. Unlike universal calipers, this is a dedicated kit that integrates the mounting bracket into the caliper design for a clean, ultra-strong installation that eliminates the flex and “mush” of factory equipment.

Differential-Bore Technology: The PM Advantage

What makes this caliper a “Differential-Bore” unit is the use of staggered piston sizes:

Leading & Trailing Balance: By using two different piston diameters, PM applies more pressure to the trailing edge of the brake pad. This compensates for the natural “pull” of the rotating rotor, ensuring the pad wears perfectly flat and maintains maximum contact surface.

Firm, Linear Braking: The 4-piston design provides a much more aggressive and predictable bite than the stock single-piston setup, allowing for shorter stopping distances with less effort at the pedal.

Engineered for the Modern Softail Chassis

Direct Fit for 25mm Axles: This kit is precision-clearanced for the 25mm rear axle found on 2008-up Softail models. It aligns perfectly with the factory 11.5″ (292mm) rear rotor.

Integrated Bracket Design: PM’s “Integrated Bore” design means the mounting bracket is part of the assembly. This creates a low-profile, “Direct Bolt-On” (DBO) solution that looks like a factory performance part rather than a clunky aftermarket add-on.

Billet Aluminum Rigidity: Machined from a solid block of 6061-T6 aluminum, this caliper resists expansion under the intense heat of heavy braking, preserving a consistent pedal feel on long descents or in heavy traffic.

Iconic Finishes & Custom Style

Three Signature Finishes: Choose from show-quality Chrome, the bold Contrast Cut (black with machined highlights), or the stealthy Black Ops (textured matte black).

Complete Kit: Every assembly includes high-performance brake pads, a bleeder screw, and a 3/8″−24 banjo bolt.

ABS Compatible: Designed to work seamlessly with both ABS and non-ABS Harley-Davidson braking systems.

Whether you’re building a high-performance “California-style” Softail or just want the peace of mind that comes with elite-level braking, the Performance Machine Rear Caliper Kit is the definitive choice.

Performance Machine Four-Piston Differential-Bore Rear Calipers For Harley Softail
Features:

Direct bolt-on calipers are machined from a single piece of billet aluminum
As the name implies, they are ready to bolt on in one piece, instead of using the more common bracket and caliper design
The brake calipers are designed for 11-1/2″ disc application and utilize the 1.37″ x 4B caliper
Compatible with ABS

Made in the USA

Fitment Notes & Exceptions

Will not fit Dyna, FXR, or Sportster models with wire spoke wheels

This Product Fits

Harley Davidson
Softail Blackline FXS 2011, 2012, 2013
Softail Custom FXSTC/I 2008, 2009, 2010
Softail Fat Boy FLSTF/I 2008-2014
Softail Night Train FXSTB/I 2008, 2009
Softail Rocker C FXCWC 2008, 2009, 2010, 2011
Softail Rocker FXCW 2008, 2009, 2010, 2011