Description
Upgrade your motorcycle's front suspension with the SD25 fork cartridges, a high-performance Separate Damping System built for bikes requiring enhanced damping control.
Designed as a larger-volume alternative to the SD20, the SD25 separates damping duties entirely between the fork legs—placing rebound damping in the right leg and compression damping in the left leg. This split layout maximizes oil flow efficiency around fewer orifices, delivering a significantly faster, more responsive damping transition when switching between compression and rebound.
The SD25 cartridges can be installed into any modern upside down or older conventional style forks. On conventional forks the chrome tube has to be 40mm diameter or bigger. If the chrome tubes are smaller than 40mm, then we recommend our SD20 fork cartridges.
Turn your mass produced non-adjustable forks, into fully adjustable custom built forks. Valved, sprung and base set for your weight, motorcycle and application.
Key Features & Specifications
• Separate Damping System (SDS): Isolates rebound in the right leg and compression in the left leg for superior oil flow efficiency.
• 25mm Piston Design: Bigger piston design for improved damping performance.
• 10mm Diameter Low-Friction Damper Rods: Hard-chromed and polished rods provide an ultra-smooth finish to optimize low-speed fork action.
• Top-Mounted Adjusters: Both rebound and compression adjusters are conveniently located on top of the fork legs, featuring 25 precise clicks for easy, confident tuning.
• Bespoke Silicon Chrome Springs: Custom-matched springs are installed in both legs, tailored specifically to your bike and individual rider weight.
• Durable Alloy Construction: Precision-machined from robust 6082 T6 and 7075 T6 alloys, then hard-anodized to protect sliding components and extend service life.
• Custom-Built to Order: Every kit is individually assembled at the factory to suit your exact machine and riding application.
• USD or Conventional forks: Adaptability to install into almost any fork.
Fork Top Options (F3 or F4 Tops)
• F3 Tops (Fully Adjustable): Includes: 30 clicks Rebound damping, 30 clicks Compression damping and 25 turns Preload adjustment.
Note: Older/conventional forks require an upper chrome fork tube diameter of 40mm or larger, suitable for both road and race use.
• F4 Tops (Reb and Comp Damping Adjustment Only): Features 20 clicks rebound damping and 20 clicks compression damping. Preload adjuster is under the fork cap/on top of the spring. Designed to reduce cost, or for conventional forks with an upper chrome tube diameter under 40mm. (Preload adjustment on F4 fork caps is handled internally via a knurled wheel beneath the fork cap)







