The BoXXer Ultimate is RockShox’s flagship downhill fork, built for riders who demand maximum composure, traction, and control on the fastest tracks. Designed around a proven dual-crown chassis with 38 mm stanchions, the latest generation introduces the LinearXL air spring and Charger 3.2 damper to deliver a ride feel that closely mimics a coil fork while retaining the tunability and weight advantages of air.

At the heart of the fork is the Charger 3.2 damper, featuring intuitive high- and low-speed compression adjustment and revised rebound and compression tunes specifically matched to the LinearXL air spring. A new numbered control bezel makes setup simple and repeatable, allowing riders to start from a defined baseline and easily fine-tune damping on the trail or at the track.

The new LinearXL air spring provides a highly consistent stroke with supple initial sensitivity, strong mid-stroke support, and a jounce bottom-out bumper that adds extra control at full compression. Combined with RockShox’s ButterCups vibration-reducing technology and the new ButterWagonTech oil distribution system that keeps the bushings continuously lubricated, the fork maintains smooth performance and reduced friction throughout the service interval.

Designed specifically for downhill racing and aggressive gravity riding, the BoXXer Ultimate delivers the stability, damping control, and durability required for modern DH tracks and bike park terrain.

Features

• Charger 3.2 damper with high-speed compression, low-speed compression, and rebound adjustment

• LinearXL air spring for coil-like sensitivity and consistent support through the stroke

• Jounce bottom-out bumper for additional end-stroke control

• ButterWagonTech lubrication system continuously supplies oil to the bushings for reduced friction

• ButterCups technology reduces high-frequency vibration and rider fatigue

• Low-friction SKF wiper seals for improved small-bump sensitivity and durability

• Dual-crown chassis with 38 mm stanchions for maximum stiffness and steering precision

• Numbered compression adjustment bezel for simple and repeatable setup

• Bolt-on fender compatibility with front and rear coverage

Specifications

• Wheel size: 29"

• Travel: 200 mm

• Offset: 52 mm

• Damper: Charger 3.2 RC2

• Spring: LinearXL air spring

• Adjustments: High-speed compression, low-speed compression, low-speed rebound

• Axle: 20 × 110 mm Boost (Torque Cap compatible)

• Stanchion diameter: 38 mm

• Steerer: Straight 1 1/8"

• Brake mount: Direct mount 200 mm

• Max rotor size: 220 mm

• Fender compatibility: Bolt-on short fender

• Weight: Approx. 2,820 g (uncut steerer)

Compatibility

Fits modern downhill bikes with 29" wheels, straight 1 1/8" head tubes, and 20 mm Boost hubs. Ensure correct axle spacing, rotor size, and offset for your frame and intended setup.

Installation Notes

Professional installation recommended unless experienced. Requires proper crown race installation, steerer tube trimming, and torque checks on all fasteners. After fitting, set sag, air pressure, and damping to suit rider weight and track conditions. Recheck crown bolts and axle torque after the first ride.