Wilwood SX6R Forged 6-Piston Radial Mount Caliper - Red | 5.40in Piston Area / 1.25in Disc (120-14860-RD)

Deliver serious stopping power to your road or track build with the Wilwood SX6R forged 6-piston radial mount caliper. The 120-14860-RD is Wilwood's largest and most capable caliper in the SX6R line — a heavy-duty, race-technology forged caliper with radial mounting, 5.40 square inches of piston area, and compatibility with rotors up to 15.00" in diameter. Finished in Wilwood's signature red and featuring an exclusive dust wiper seal system for environmental protection, the SX6R is engineered for the most demanding braking requirements on the road or track.

Note: Universal caliper — requires a custom bracket or application-specific adapter for installation. Verify rotor diameter, disc thickness (1.25in), and mounting configuration compatibility with your specific application before ordering. This is a single caliper — order two for a complete axle.

Key Features:

• Forged 6-piston caliper — Wilwood SX6R series
• Radial mount design for widespread adaptability
• 5.40 square inches of piston area
• 1.25 inch disc (rotor) thickness
• Compatible with rotors up to 15.00" diameter
• Exclusive dust wiper seal — protects piston bore from dust and corrosion
• Red anodized finish
• Multiple piston volume options available in SX6R line
• 11.6 lbs

Performance Benefits:

• 6-Piston Forged Construction: Six pistons provide even pad pressure distribution across the full pad face, maximizing pad contact and braking efficiency. Forged aluminium construction provides maximum strength with minimum weight compared to cast alternatives
• 5.40in Piston Area: Large total piston area generates substantial clamping force for heavy-duty braking requirements — suited to heavy vehicles, high-speed applications, and sustained track use where maximum braking force is required
• Radial Mounting: Radial mount design provides a more rigid caliper-to-upright connection than traditional lug mount designs, reducing caliper flex under hard braking and improving pedal feel and braking consistency
• 15.00" Rotor Compatibility: Supports rotors up to 15 inches in diameter, providing the leverage and swept area needed for maximum braking torque on heavy or high-speed applications
• Dust Wiper Seals: Exclusive dust wiper seal system protects the piston bore from dust, debris, and corrosion — extending caliper service life and maintaining consistent piston function in road and environmental use
• Environmental Sealing: Dust wiper seals satisfy environmental sealing requirements in locales that mandate such protection, making the SX6R suitable for street-registered vehicles in regions with such regulations

Specifications:

• Brand: Wilwood Engineering
• Part Number: 120-14860-RD
• Series: SX6R
• Piston Count: 6
• Construction: Forged aluminium
• Mount Type: Radial
• Piston Area: 5.40 square inches
• Disc (Rotor) Thickness: 1.25 inches
• Maximum Rotor Diameter: 15.00 inches
• Finish/Colour: Red anodized
• Sealing: Exclusive dust wiper seal
• Weight: 11.6 lbs
• Barcode: 889545084306

Fitment and Application:

• Universal fitment — requires application-specific bracket or custom fabrication for installation
• Suited to heavy vehicles, high-performance street builds, and track applications requiring maximum braking force
• Compatible with 1.25" thick rotors and rotors up to 15.00" diameter
• Note: Single caliper — order two for a complete axle set
• Note: Verify pad availability for SX6R caliper before ordering — confirm pad compound options for your intended use
• Note: Brake lines, fittings, and mounting hardware not included — must be sourced for your specific application
• Installation: Professional installation required — custom brake system fabrication and setup expertise needed

What's Included:

• Wilwood SX6R forged 6-piston caliper — red (120-14860-RD), single caliper
• Note: Brake pads, mounting bracket, brake lines, and hardware not included — verify with Wilwood documentation

Installation Notes:

• Professional installation required — custom brake system expertise needed
• Design and fabricate or source a caliper mounting bracket for your specific upright and rotor diameter
• Verify caliper clearance to wheel, tyre, and suspension components before finalizing bracket design
• Use Wilwood-recommended brake fluid and bleed procedure
• Bed brake pads after installation per Wilwood's recommended bedding procedure
• Inspect all brake system components for leaks after installation and before track use
• Verify brake bias with front/rear caliper and master cylinder sizing for your specific vehicle and application

Wilwood SX6R — Race Technology for Road and Track:

The Wilwood SX6R represents the top of Wilwood's radial mount caliper lineup — a forged 6-piston caliper designed to deliver race-level braking performance in a package that is adaptable to a wide range of heavy-duty road and track applications. The SX6R's design incorporates several technologies developed through Wilwood's extensive motorsport involvement: forged aluminium construction for maximum strength-to-weight ratio, radial mounting for maximum caliper rigidity, and a multi-piston design for even pad pressure distribution and maximum braking efficiency.

The SX6R's defining feature relative to other Wilwood calipers is its scale — with 5.40 square inches of piston area and compatibility with rotors up to 15 inches in diameter, it is designed for applications where maximum braking force is the primary requirement. This makes it suited to heavy vehicles (trucks, SUVs, large performance cars), high-speed applications where large rotors are needed for thermal capacity, and sustained track use where the brake system must manage repeated high-energy stops without fade.

Radial Mounting — Why It Matters:

Traditional brake calipers use a lug mount design — the caliper is bolted to the upright or knuckle through lugs that are part of the caliper body. Under hard braking, the braking torque is transmitted through these lugs, which can flex slightly under load. This flex reduces the rigidity of the caliper-to-upright connection, which can cause the caliper to move slightly relative to the rotor under hard braking — reducing braking efficiency and contributing to a soft or inconsistent pedal feel.

Radial mounting addresses this by bolting the caliper to the upright through a face that is parallel to the rotor face — the mounting bolts are oriented radially relative to the rotor. This provides a more direct, rigid connection between the caliper and the upright, reducing caliper flex under braking torque and providing a more consistent, firm pedal feel. Radial mounting is the preferred design for high-performance and racing brake calipers, and is standard on the SX6R.

Dust Wiper Seals — Environmental Protection:

The SX6R's exclusive dust wiper seal is a secondary seal that sits at the outer end of each piston bore, in addition to the primary hydraulic seal. The dust wiper seal prevents dust, debris, and moisture from entering the piston bore from the outside — protecting the piston and bore surface from contamination and corrosion that can cause piston sticking, uneven pad wear, and caliper failure over time. This is particularly important for road-driven vehicles that are exposed to road grime, water, and salt, and for vehicles used in dusty environments such as off-road or desert track applications.

The dust wiper seal also satisfies environmental sealing requirements in jurisdictions that mandate such protection for street-registered vehicles — making the SX6R one of the few high-performance racing calipers that can be legally used on street-registered vehicles in regions with such regulations.

Why Wilwood?

Wilwood Engineering is one of the most respected brake system manufacturers in North American motorsport, with decades of experience developing brake components for drag racing, road racing, oval track, and off-road competition. Their calipers, rotors, and master cylinders are used across a wide range of professional and amateur motorsport categories, and their engineering expertise is reflected in the quality and performance of their products. For builders who need a heavy-duty, race-proven 6-piston caliper for a demanding road or track application, Wilwood's SX6R is a benchmark choice.

Perfect For:

• Heavy vehicle brake system builds (trucks, SUVs, large performance cars) requiring maximum 6-piston braking force with large rotor compatibility
• High-speed track builds wanting radial mount 6-piston calipers with large rotor support for maximum braking torque and thermal capacity
• Custom brake system fabricators building bespoke brake setups for demanding road or track applications
• Street-registered performance builds in regions requiring environmentally sealed calipers — SX6R dust wiper seals satisfy these requirements
• Anyone needing Wilwood's largest, most capable radial mount 6-piston caliper for a heavy-duty braking application

Perfect For: Heavy-duty road and track brake builds requiring Wilwood SX6R forged 6-piston radial mount caliper with 5.40in piston area, 1.25in disc, up to 15in rotor compatibility, and dust wiper environmental sealing.

Pro Tip: When sizing a brake system around the SX6R, work backwards from your target braking force and pedal feel — the caliper's 5.40in piston area must be matched to an appropriate master cylinder bore size and pedal ratio to achieve the desired pedal effort and feel. A caliper this large paired with a master cylinder that is too small will result in excessive pedal travel; paired with one that is too large will result in a very firm pedal with limited modulation. Wilwood's brake system calculator is a useful starting point for sizing the complete system.

SX6R | 6-Piston | Forged | Radial Mount | Red: Universal — requires custom bracket. Single caliper — order 2 for axle set. 1.25in disc. Up to 15in rotor. Dust wiper seals. 11.6 lbs. Professional installation required.

Deliver maximum stopping power with Wilwood 120-14860-RD SX6R — forged 6-piston radial mount caliper, 5.40in piston area, 15in rotor compatible, dust wiper seals, red finish for demanding road and track applications.