The SD25 cartridges are a larger version of the SD20 cartridges. These are better suited to bikes where more damping is required.

The SD25 fork cartridges are a Separate Damping System. This means all the rebound damping is in the right leg and all the compression damping in the left leg. The main advantage of this is improved oil flow. Oil can flow faster around the damping system, as there are less orifices to flow through. This gives much better damping response when the action of the fork is changing from rebound to compression, or vice versa.

Another advantage of separating the damping between the legs, is the adjustment is very quick and easy to access. Normally if you have damping adjusters on top of the forks they are both rebound damping adjusters. The compression damping would be situated at the bottom of the fork, and is normally not adjustable. Because the SD25 cartridge separates the damping between the legs, it has a rebound damping adjuster on the top of the right leg and a compression damping adjuster on top of the left leg. Both damping adjusters also click to make the adjustment more accurate and easy to understand. If you are not used to adjusting suspension, this gives you more confidence to adjust the forks.

The damper rods on the SD25 cartridges are hard chromed and polished for a hard smooth finish. This improves the low speed action of the cartridge, improving the mid corner feel and making the front forks more compliant.

The SD25 fork cartridges have springs in both legs. The springs are manufactured to our design from Silicone Chrome. The spring rate is chosen to suit the weight of the bike and also your rider weight.

If the diameter of your upper fork tube is 40mm or larger, we can offer preload adjustment to your SD25 fork tops.

If the diameter of your fork tube is smaller than 40mm its is not possible to add preload adjustment to the fork tops. Instead we have come up with an internal adjustable preload system. To access this you simply undo the chrome tube to expose the top of the spring. On top of the spring is a knurled wheel that screws up and down a thread. To adjust the preload you simply undo a lock nut and wind the knurled wheel up or down.

SD25 CARTRIDGE OVERVIEW :

• Modern Separate Damping cartridge
• Improved oil flow for better damping performance
• All damping adjustment at the top of the fork for easy access
• 25 clicks of rebound damping adjustment
• 25 clicks of compression damping adjustment
• Hard chromed damper rods for smoother cartridge action
• Silicone Chrome fork springs chosen to suit your weight
• Machined from 6082 T6 and 7075 T6 Alloy
• Hard anodised to prevent wear and prolong life of sliding componants.
- Built to order, to suit each bike and each riders weight

We supply the SD25 cartridges with two different designs of fork top. One fork top design has rebound damping, compression damping and preload adjustment. The other fork top design has rebound damping and compression damping adjustment only.

SD25 FORK CARTRIDGES WITH REBOUND DAMPING, COMPRESSION DAMPING AND PRELOAD ADJUSTERS - F3 TOPS

The F3 fork tops are our fully adjustable fork tops for the SD25 cartridge. These give you adjustable rebound damping, compression damping and preload adjustment.

We can only fit these fork tops if the upper tube diameter is 40mm or larger. This fork top is suitable for road and race bikes. The rebound and compression damping adjusters have a range of 25 clicks and the preload has a range of 25 turns.

SD25 CARTRIDGES WITH REBOUND AND COMPRESSION DAMPING ADJUSTMENT ONLY – F4 TOPS

The F4 tops only adjustable for rebound damping and compression damping. The F4 fork tops are used when the customer would like to reduce the cost or when the outside diameter of the upper fork tube is smaller than 40mm. When the outer tube diameter is less than 40mm it means there is not enough room to include preload in the fork top. There is still a way of adjusting the preload on the F4 fork tops, but the fork tops must be undone from outer tubes – see description above.