Fox 40
with optional ABS
(only needed for
older oem factory
coil only forks)
and optional
FvAT/HSB installed

Fox 40/49 and Marzocchi Bomber 58
Open Bath Cartridge and Adaptor Kit




The best performance modification you will ever do to your fork!

Complete replacement of the damper with our open bath cartridge!

This will make your fork feel like a completely different fork, because it is!

Low speed damping that’s firm but still blows-off to be plush on small bumps,
Reduced fork dive that eases the fork through the travel without harshness,
No more high speed compression spikes and no more bottoming with the optional ABS system.

Low speed compression and rebound adjusters help fine tune the valving as to
how it transitions from low to mid and when the high speed kicks in.
Much more effective than the other dampers attempt to add high speed adjustment without the proper shim stack.

Open Bath Cartridge system for better lubrication, smoother action and virtually maintenance free.

External low speed compression and low speed rebound adjusters

Internal revalvable custom high speed compression and rebound valving.

Internal Anti-dive Midvalve.

Optional ABS when using coil kits and when air progression is not enough to prevent bottoming

Optional FvAT/HSB System

Includes the 20 mm Cartridge Damper Kit Insert and fork cap adaptor.

Self install kit, user serviceable and revalvable.

All cartridges are optimized for current travel.
If you plan on changing the travel in the future, please let us know so the proper cartridge tube can be installed.


For details on Cartridge click here:

To order tools, revalving kits, and replacement adaptors click here:

Weight grams 300 grams plus oil.
(Fox Fit RC2 Cartridge -approx.300 grams filled with oil).



• Replacement open bath maintenance free speed sensitive damper assembly, "set it and forget it"
• 20 mm ID damper tube with shimmed 4 port MX style compression and rebound valving pistons
• Upper fork cap adjuster screw with 22 clicks of activated low speed rebound
• Base valve adjuster screw with 22 clicks of activated low speed compression adjustment
• Optional Hydraulic Anti-Bottoming System (ABS) for end of stroke bottoming resistance
• Speed sensitive multi-stage shimmed compression, midvalves and rebound valving
• Custom valved and set-up for each rider with printed set-up charts
• Fork spring and air pressure recommendations help us tune to to your weight riding style
Midvalve kit included with standard cartridge to prevent fork dive, adds low speed compression without
harshness, optional midvalve revalving shim kit and set-up charts available
• Designed to be self-installed or send it to us for installation if you need us to do the install

• Weight approx. 300 grams

Need us to install it for you, just send your fork to us and we will install it for $129 including Spectro 85/150 oil.

*Self install kit assumes good working knowledge of internals and service procedures.

Includes New Interactive Set-Up Chart


• Optional FvAT/HSB
Floating Valving Assisted Threshold High Speed Blow-off System

click here to add it to your cartridge

For the firmer feel without harshness, have that big hit set-up that still feels plush on square edged bumps!

Available for those who want to fiddle with their set-up:
Optional revalving kit for compression and rebound pistons, with revalving set-up charts



Fox 40 Hybrid Coil
Open Bath Cartridge



Our new Hybrid Coil option for the open bath Cartridge System
add option below

Cartridge Cut-away View


Compression, Rebound and Midvalve shown above.


Purchase Here

Fox 40/Bomber 58 Open Bath Cartridge Kit including fork Cap Adaptor
and Midvalves installed, $549
(Cartridge Damper only, Hybrid Coil sold separately)

Download:Cartridge Installation and Set-up Manual beta(3 MB)

Watch(stream google)the Install Video(unedited sorry)

Watch smaller video file(387 MB)

Custom valved and set-up to rider weight, ability and riding style

Need to have us install it for you? Ship your fork to us and we can install it for $129 plus shipping, includes Spectro 85/150 oil.


Choose the type of riding that you will be doing so we can custom valve it to your specific needs.

Click here for a description of our definitions

Type of Riding

Choose your fork year that the cartridge will be installed in.

Fork Year

Choose your fork model that the cartridge will be installed in.

Fork Model

Choose your fork travel (mm) that the cartridge will be installed in.
For Talas forks choose the travel you want the set-up optimized for.

Fork Travel

Choose your fork wheel size that the cartridge will be installed in.

Fork Wheel size

Choose rider weight.
Rider weight is without gear, we add 5-7 lbs for DH gear, 7-10 lbs for All-Mtn/Freeride.

Rider Weight

Choose the spring rate/air pressure you will be using which gives you 22% sag.
We need this number to help set-up your fork rebound damping correctly.

Click here for sag setting Tips


Air Pressure
or Spring Rate

Choose your rider ability for us to set-up the cartridge.

Rider Ability




Add option here
Our new Hybrid Coil and Cartridge System

The coil kit supports about half the rider weight and the air spring makes up for the other half of the support needed. Now the air side can be used to fine tune the spring rate needed as well as adjust the ride height for different riding conditions, also the air ramp-up can be controlled with the traditional tokens or aftermarket ramp up adjustment devices. The advantage of the hybrid system is versatility, performance, weight, and cost savings. It simply drops into the damper side, only adds about 178 grams(250 grams for 8 inch fork), it solves most of the air spring issues in the first half of the stroke, where the friction forces and small bump compliance are critical, more supportive, it fills in the midstroke wallow of the air spring and corrects the ride height with physical adjustable preload. When the fork gets deeper in the stroke the spring force is more dominant and the stiction and air spring concerns are not as noticeable, so the final spring force is not as sensitive as long as it is more linear and removal of the tokens is now possible with proper damping. The air spring can be set to very low pressures and as linear as possible where it is nearly negligible. Ride height and spring rate can be fine tuned with the air spring pressure which is very helpful when in between spring rates and allows for different riding conditions. The equal force system is a very important feature because now the fork compresses equally with about the same spring rate in both stanchions, a single spring system causes the unsprung side to compress ahead the spring side because of the flexibility of the crown and lowers, this causes stiction in the first half of the travel which is more of a contributor than the air spring stiction. The abs system that we sell as an option to our damper and the Vorsprung system is not necessary because of the air hybrid ramp up is sufficient to prevent bottoming. We feel because of all these advantages there is no need to remove the air spring for single crown fork and replace it with a empty leg coil system.

Download: Hybrid Coil Air Cartridge Installation and Set-up Manual beta(3 MB)

Watch(stream google)the Install Video(unedited sorry)

Watch smaller video file(387 MB)

Only available as an open bath cartridge system option.


Click here: to add for Fox 40/Bomber 58 Hybrid Coil Option


ABS Option

Only needed for older coil forks, not needed for Hybrid Coil/Air Forks

Click here for more details

We prefer to control bottoming with the use of our optional ABS on the damper side.
This will create a more linear spring system without any mid to end stroke ramp-up and will improve deep square edged hits and better control on jump faces.

Add option here

Price $99.95

Price $99.95, during initial build.

Price $99.95, plus labor($99) to retro fit, send your cartridge to us for installation.






Have us install your cartridge for you

Ship us your fork, we will install your new cartridge,
service and rebuild your air spring with our improved air transfer sealing system, 2015-2017 Models
replace seals and relube.
includes Spectro 85/150 Oil

Add option here, does not include shipping back to you, we will adjust your shipping total depending on where you live in the world and send you a Paypal invoice for the difference. It assumes your fork is in good working condition with no physical damage or scratches on the stanchions.

Add each item required to the cart. Price $129


Installation and Service

Price $129, plus shipping difference