Elite Control: Performance Machine 4-Piston Differential-Bore Front Calipers (1984–1999)

Give your Evolution-era Harley the braking performance it deserves with the Performance Machine (PM) 4-Piston Differential-Bore Calipers. Stock brakes on 1984–1999 models are often the weakest link in the riding experience; PM solves this with a precision-engineered, bolt-on solution that provides a massive increase in clamping force and superior heat dissipation.
The Power of Differential-Bore Engineering

The “Differential Bore” design is the secret to PM’s legendary performance:

Balanced Friction: By using two different piston diameters (one smaller leading piston and one larger trailing piston), the caliper applies pressure more effectively across the brake pad. This prevents “tapered” wear and ensures a consistent, aggressive bite every time you grab the lever.

Firm Lever Feel: These calipers are CNC-machined from high-strength 6061-T6 billet aluminum. This rigid construction eliminates the “flex” common in older cast-aluminum factory calipers, providing a stiff, communicative lever feel that lets you know exactly how much traction you have.

Modern Performance for Vintage Iron: Designed specifically for the 1984–1999 mounting pattern, these allow you to run modern 4-piston technology on Softail, Dyna, Sportster, and Touring models without the need for messy adapter brackets.

Premium Styling and Finishes

Reduced Unsprung Weight: The lightweight billet design improves suspension tracking and front-end handling by reducing the weight the fork has to control.

Finish Options: * Chrome: A high-luster, show-quality finish.

Contrast Cut: Black anodized with hand-machined highlights for a modern look.

Black Ops: A rugged, textured matte black that matches PM’s other Black Ops accessories.

Low Maintenance: Built with high-grade internal seals and stainless steel pistons to resist corrosion and ensure long service intervals.

Fitment and Technical Specs

Compatibility: Fits most 1984–1999 Harley-Davidson models with single or dual front discs (excluding Springer models).

Brake Pads: Includes high-performance organic pads designed for strong initial bite and minimal rotor wear.

Standard Hardware: Utilizes 1/8″−27 NPT inlet (standard for many PM calipers of this era) or 10mm depending on the specific SKU.

Transform your classic ride into a modern performer. Performance Machine Calipers are the industry standard for those who refuse to compromise on safety or style.

Performance Machine Four-Piston Differential-Bore Front Calipers For Harley

High performance pads and stainless lines are only half measures. If you want to really upgrade the stopping power on your Harley replace your front caliper with a 4 Piston Differential Bore Caliper from Performance Machine. Trust the leading name in V-Twin brakes to handle the stopping duties on your machine.
Features:

Caliper is 4 piston differential bore with dual pad design
Differential bore pistons apply different forces at the leading and trailing edge of the pad to ensure long life
Designed for 11.5″ and 11.8″ disc applications
Requires 11/16″ master cylinder 501-058, or 501-057 or 501-059 for optimal performance

Made in the USA

Fitment Notes & Exceptions

Calipers listed for 2000-2003 Sportster models will fit 2004-2013 models if used with a 9/16″ bore master cylinder
Will not fit Dyna, FXR, or Sportster models with wire spoke wheels

This Product Fits

Harley Davidson
Dyna Low Rider FXDL/I 1993-1999
Dyna Super Glide FXD/I 1995, 1996, 1997, 1998, 1999
Dyna Super Glide Sport FXDX 1999
Dyna Wide Glide FXDWG/I 1993-1999
Electra Glide Classic FLHTC/I 1984-1999
Electra Glide Special FLHX 1984
Electra Glide Sport FLHS 1984-1993
Electra Glide Standard FLHT/I 1984-1999
Electra Glide Ultra Classic FLHTCU/I 1989-1999
FLH 1984, 1985
FXR2 CVO/SE 1999
FXR3 CVO/SE 1999
Low Glide/Low Rider FXRS 1984-1993
Low Rider Chrome FXRC 1985, 1986, 1987, 1988
Low Rider Custom FXLR 1987-1994
Low Rider Sport FXRS-SP 1987-1993
Road Glide FLTR/I 1998, 1999
Road King Classic FLHRC/I 1998, 1999
Road King FLHR/I 1994-1999
Softail Custom FXSTC/I 1986-1999
Softail Fat Boy FLSTF/I 1990-1999
Softail Heritage Classic FLSTC/I 1987-1999
Softail Nostalgia FLSTN/I 1993
Softail Special FLSTN/I 1994, 1995, 1996
Softail Standard FXST/I 1984-1999
Sport Glide FXRT 1984-1992
Sport Glide Grand Touring FXRD 1986
Sportster Custom XL1200C 1996, 1997, 1998, 1999
Sportster Custom XL883C 1998, 1999
Sportster Deluxe XLH883DLX 1989, 1990, 1991, 1992
Sportster Hugger XLH883HUG 1988-1999
Sportster Sport XL1200S 1996, 1997, 1998, 1999
Sportster XLH1100 1986, 1987
Sportster XLH1200 1988-1999
Sportster XLH883 1986-1999
Super Glide FXR 1986-1994
Tour Glide Classic FLTC/I 1984-1991
Tour Glide FLT 1984, 1985, 1986
Tour Glide Ultra Classic FLTCU/I 1989-1996
Wide Glide FXWG 1984, 1985, 1986
XL 1984
XLH1000 1984, 1985
XLS Roadster 1984, 1985
XLX-61 1984, 1985