The GP20 front fork cartridges have been designed to replace the internals in forks where the original damping system is very basic or sealed. The GP20 fork internals are designed to fit into any fork where the bore of the stanchion is 27mm or bigger. Each cartridge is built to order so we valve the cartridge to suit the bike and what the bike is being used for. The cartridges also are supplied with springs to suit rider weight and the bikes weight.

The GP20 cartridges have been designed and developed by our own technicians. All of the components are machined at Maxton by our engineers, so we can closely control the quality of all the components. The cartridges have been machined from a high grade 6082 and 7075 Alloy and hard anodised to protect the internals from wear. The springs used in the GP30 cartridges have been manufactured from Silicon Chrome to our own specification. They are rate checked by the manufacturers, then by our own engineers using our own equipment to ensure they are correct.

The GP20 cartridges have separate rebound and compression damping pistons with shims stacks chosen to suit what you are using the bike for. The cartridges are supplied as a pair, they have rebound and compression damping in both legs. There are three different options of GP20 cartridge we supply with different levels of adjustment :

OPTION 1 - has rebound damping adjustment only.
OPTION 2 has rebound damping and compression damping adjustment
OPTION 3 has rebound damping, compression damping and preload adjustment

In most cases the cartridges come with new fork tops.

In a lot of modern forks nowadays the original damping system is sealed or tamperproof, this means we can not strip and revalve the original cartridges. In these cases all we can do improve the forks is replace the original damping system with a GP20 cartridge. The most common modern forks we supply cartridges for are Triumph Street Triple and Tiger forks, SV650 forks, ER6 forks and Ducati Hypermotard forks.

We supply a lot of GP20 cartridges for classic front forks. Because of this we have designed special valving to suit the classic tyres and weights of the classic bikes. We have also had a range of springs made to suit different classic bikes. In most cases the original classic bottom sliders have to be machined to accept the GP20 cartridges. The most popular classic forks we fit GP20 cartridges to are Manx Norton forks, Ceriani forks, Honda forks, Triumph forks and Marzocchi forks. All these forks have 35mm or 38mm stanchions. In some classic forks we have to machine new bushes to improve the action of the sliders before we install the GP20 cartridges.


  • Designed to fit any fork with a stanchion diameter of 34.50mm or bigger
  • Designed, developed and manufactured by our team of engineers and designers at Maxton
  • Separate 20mm rebound and compression damping pistons with shim stacks
  • All components hard anodised to prevent wear
  • Each pair of cartridges are valved and sprung to suit the rider
  • Wide range of damping adjustment
  • Rebound damping adjustment
  • Compression damping adjustment
  • Preload Adjustment
  • Silicon Chrome springs, rate checked by Maxton after manufacture
  • Maxton's technical back up and support