GP Suspension, 25mm Cartridge Kit for HD Baggers 14' - 25'

Race-Developed. Road-Ready. Built for the Ultimate Bagger Ride.

GP Suspension’s cartridge kit for Harley-Davidson baggers features the same innovative design originally developed on the racetrack. This advanced hydraulic system is engineered to absorb every imperfection in the road, giving riders exceptional confidence, comfort, and traction. Drawing from an extensive racing background, GP Suspension has crafted a suspension that is not overly stiff like typical race setups, but finely tuned for high-performance road use.

With a deep understanding of suspension dynamics, GP Suspension delivers a smooth, controlled ride that enhances comfort without compromising responsiveness or stability. Experience the perfect blend of race-proven technology and street-tuned comfort.

Three-Valve Advantage:
Unlike typical two-valve systems, GP Suspension’s three-valve design includes a base valve alongside the rebound and compression valves. This configuration allows for superior fluid control and pressure management, minimizing cavitation and harshness. The base valve delivers a plush response during low-speed compression and ramps up under heavier impacts—perfect for everything from potholes to high-speed hits—ensuring consistent traction and comfort in any condition.

Tailor-Made for Every Rider:
Every kit is custom-built using rider-provided specs such as weight, bike setup, and riding preferences. A spring set is selected by a GP Suspension technician to perfectly match your riding profile, ensuring optimal performance right out of the box.

100% American Made:
All engineering and machining are done entirely in-house at GP Suspension’s Ventura, CA facility. Nothing is outsourced—every component of the kit is proudly American made.

The GP Suspension cartridge kit is fully adjustable for preload, compression, and rebound, with all tuning accessible directly from the fork caps. This allows riders to fine-tune their suspension to suit personal preferences or changing road conditions. The kit also increases fork stroke from 117mm to 122mm, offering better compliance and control for a smoother, more responsive ride. GP Suspension’s three-valve system—featuring base, compression, and rebound valves—delivers superior fluid dynamics and pressure control compared to traditional two-valve designs. For those seeking more ground clearance or a custom geometry setup, GP Suspension offers custom-length configurations; riders simply need to supply longer chrome fork tubes for these builds. Additionally, optional pre-modified fork tubes are available to simplify installation for those who prefer a ready-to-fit solution.

Installation Notes:

• Slight modification to upper fork tubes required due to the larger-diameter piston

• OEM bottoming assembly must be removed

• Watch the installation video here

2024 ABS Models: Riders going 2" over will need extended lower brake lines. GP Suspension recommends Magnum 2" over lines for dual disc ABS setups.

Included in Pricing:

• A spring set chosen by a GP Suspension setup technician based on your riding information

Questions? GP Suspension is always available to help with setup or custom build inquiries. Contact GP Suspension directly for guidance or to request a custom configuration.