Original equipment motorcycle forks are generally a compromise, being engineered to achieve reasonable performance without great manufacturing costs, and also being set up for an average weight rider under average riding conditions.

    So of course the performance of your forks can be significantly improved in terms of matching spring rating, damping, and also adjustability to you and the way you ride. You will get improved resistance to front brake dive, better front end stability and cornering, and improved bottoming control.

    We stock fork cartridge kits from three manufacturers - Progressive, Bitubo and Matris. Ranging from not too expensive to ouch, you get what you pay for, which is a significant increase in front end performance at all levels from cruising to racing.

    We can also supply the top quality US-made LEGEND AXEO cartridge kits, which are designed to give most of the Harley range including Tri Glide trikes top quality fork cartridges, priced mainly at £865/pair delivered.


US-based Progressive make 3 variants of their fork cartridge kits, mainly for Harleys but also for KLR650 and GL1800's. Most of the kits are also available in lowering versions.
No modifications to the OEM forks are required.

Basic monotube kits are available for 1997-2013 Harley Tourers, 2000-2014 Softails, 2004-2014 Sportsters, KLR650 2008-on and GL1800 2001-2014.

The kits comprise two high performance gas charged monotube cartridges paired with replacement progressive fork springs, and will replace and significantly improve on either dual damper rod or damper rod/cartridge forks.

Lowering kits generally allow up to 2" drop, though not on designated Low models.

Price from £295/pair delivered.

Mainly for 49mm-forked Harley Dynas these fork cartridge kits are asymmetrical. They replace all the original fork internals with an aluminium-bodied sealed cartridge damper in one fork leg, and a preload adjuster over a new progressive rate spring in the other leg.

Applications are listed for Harley FXD's 2006-2017 (except FXDF), and 2016-2017 XL1200X.

Can be installed for either standard height or 1" lower.

Price from £495/kit delivered.

Progressive's recently introduced top specification kits use FST (Frequency Sensing Technology) damping valves to ensure optimal damping under varying ride conditions.

High performance front suspension is now available for 2014-on Harley Tourers. The road-smoothing FST damper is asymmetrically mated with a progressive rate spring to create a state of the art fork cartridge kit for late model baggers.

Progressive use FST valves in their highly-rated 444-series twin shock absorbers

The kit is supplied fully assembled and sealed with the oil inside, and no modification of the original forks is needed.

Lowering versions also available. Price from £595 delivered.


Bitubo are at the forefront of front end performance, always driven by the need to improve and win even more races.

Their mid-range JBH kits are excellent, and increasing sales are recognising their real value for money.

A number of Moto Guzzi's were fitted with Bitubo cartridges from new. The ABA range is the updated replacement for these Guzzi cartridges, covering V35 1977-1987; V50 1977-1984; V65 1982-1988; LM I/II/III 1975-84; California T3 850 1979-1985; California 1000 Mk II 1981-87; and V1000 1975-1984.

The kits comprise two nitrogen pressurised cartridges and fitting instructions.

A fast replacement of the original cartridges, they improve the legendary stability and handling of your Moto Guzzi.

Price £215/kit delivered.

Bitubo JBH fork cartridges are a performance upgrade available for around 50 models of sports bikes. They have separate cartridges (damper plus linear spring) for each fork leg, with one leg having 12 clicks of rebound damping adjustment plus 5mm of added preload, while the other leg has 12 clicks of compression damping adjustment and a further 5mm of added preload.

Price from £540/kit delivered.

Bitubo's race developed ECH29 fork cartridges feature their most advanced technological innovations. Their Full Pressure System (FPS) provides immediate fork oscillation damping and prevents fluid cavitation, via low pressurisation gas and double-ended reservoirs.

Featuring special light Ergal alloys for minimum weight, they are asymmetrical with 24-clicks of rebound damping plus preload in one fork leg and 24-clicks of compression damping plus preload adjustment in the other.

Also features special easy-changer system which allows spring or damper changes without removing the forks.

Available for more than 80 bike models, and no modification of the original forks is needed.

Price £1190/set delivered.


Manufactured in Italy to the highest quality, Matris fork cartridge kits are designed to give a major improvement to the ride and controllability of nearly 300 bike models, with the emphasis on sports bikes, track days and racing.

F12 Kits replace all the original fork internals, with no modifications, on bikes with adjustable forks. Both the 20mm (F12S) and 25mm (F12R) versions use a 12mm pumping rod and compression and rebound pistons machined from aluminium billet, with its own dedicated shim stack and supported by oilless slide bearings.

The spring preload, rebound and compression adjusters are all click-type, and the kit includes springs, valve set for compression adjustment (where provided for by the original) and oil. Springs are linear and different rates are available.

Price from £746 delivered

F15K completely replaces all the original fork internals to modify a conventional non-adjustable fork into a fully adjustable fork with spring preload, rebound and compression damping adjustment.

The kit houses the rebound damping in one fork leg and the compression damping in the other. Springs are linear and different rates are available.

It can be fitted with no modifications whatsoever, and can be removed again if you sell your bike.

Currently around 70 applications, more being added. Most are priced at £542 delivered.

FS25SA are Matris's top of the range cartridges, designed full full-on race use. All lightweight materials are used. The kit houses a 38-click rebound adjustable damper in one fork leg, a 38-click compression adjustable damper in the other leg, and preload adjusters on both legs. Each leg has its own shim-stack type valve supported by oilless slide bearings, and an integrated expansion tank greatly reduces any cavitation. Springs are linear and different rates are available

The kit is supplied fully assembled and sealed with the oil inside, and no modification of the original forks is needed.

Currently around 60 applications, more being added. Most are priced at £1139 delivered.

Choose your Cartridge Kit:
Progressive monotubes from £295
Progressive preload adjust kit from £495
Progressive FST-type kit from £595
Bitubo ABA kit £ 215
Bitubo JBH kit £ 540
Bitubo ECH kit £ 1190
Matris F12 kit from £ 746
Matris F15K kit from £ 542
Matris F25SA kit from £ 1139
Legend AXEO kit from £ 865