2014 shown with
optional ABS

Fox 34 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 and optional ABS system for better lubrication, smoother action and bottomless feel.

External low speed compression and low speed rebound adjusters

Internal revalvable custom high speed compression and rebound valving.

Internal Anti-dive MidValving.

Optional ABS when air ramp-up is not enough to prevent bottoming

optional FvAT/HSB System

Self install kit, user serviceable and revalvable

Optional ABS recomended for older non-adjustable air volume systems

ABS not recommended for smaller travel set-ups of 150-120 mm

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.

Talas travel positions are still functional as only the damper side is modified.
It will work in all travel modes, the tune can be set for a best compromise between
the two or we can set it up for the higher travel mode, because this is the more sensitive position generally used for DH. When set to the reduced travel mode we suggest that you stiffen the suspension up with the clickers, same as you did with the stock damper.

Available for all models, FIT or Evolution, Grip, including 26, 27.5 and 29er


• 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 air pressure recomendations 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

Currently using Fox air caps adapted to our cartridge rebound adjuster assemblies.

Fox 34 Open Bath
Cartridge Kit
Section view

standard cartridge

shown with optional ABS

2014 shown with optional ABS

Order Here

Fox 34 Open Bath Cartridge Kit including adaptors
and Midvalves installed, $499

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

Download: Fox 34 Cartridge Installation and Set-up Manual Rev A(24 MB)

Need to have us install it for you? Ship your fork to us and we can install it for $129 plus shipping, includes Spectro 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 the cartridge will be installed in.

Fork Year


Choose your fork model that the cartridge will be installed in
Makes no difference if it is FIT or Evolution as the damper is completely replaced with our cartridge.

Fork Model

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

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

Click here for sag setting Tips



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

Rider Ability






ABS Option

Click here for more details

Add option here

For coil conversions or where bottoming issues presist.

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
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. This is not a rebuild, it assumes your fork is in good working condition with no leaks or scratches on the stanchions.

Price $129


Installation and Service

Price $129, plus shipping difference







-Hydraulic bottom out on your cartridge in my 888 is wonderful. Is it a useful in a trail style air fork? Or should it be omitted? Or purchased and used as a matter of personal preference/tuning. In past bottoming my trail fork has never been much of an issue for me, possibly because I like to keep the air pressure high to keep the mid stroke firm.

Most air forks the abs could be omitted, for very linear air curves and lighter riders with low pressures the air does not ramp up much so they still could benefit from the ABS. We do recommend that the air pressure only be used for setting sag, volume spacers or reducing the air volume is a better method for increasing progression. The midvalves will keep the fork higher in the stroke when the cartridge is installed. The pike cartridge does not include the abs, it is sold as an option.

-I'll be running this fork primarily on low speed east coast chunk with the occasional run down a DH mountain. I assume a reasonable tune can still be achieved for the low speed trails. A good average moving speed on my local trails is about 7-8km/h for a reasonably fit non-pro rider. Very few drops/jumps, nothing bigger than 2-3 feet on the trail bike. My primary concern would be getting good brake dive support without an overly harsh feel.

This is where our cartridge can work the best, with a firmer midvalve and light low speed compression the fork exhibits the best of both worlds. The midvalve will blow-off as it hits the bumps, it feels like the low speed is set firm but opens as it hits the small bumps.

-I see a price drop for air forks on the pike page. Does this apply to the 34 as well?

The pike is the first cartridge we started offering without ABS, this accounts for the price difference. We can offer it as an option on all air fork cartridges, just ask.

-I see on the pike page a compression adjuster knob kit being available. Available on the fox 34? Any chance I can get one early. I believe in past you've not wanted to do a compression adjuster knob due to the risk of damage to the cartridge, has this been overcome?

The knobs are being made as we speak, hope to be adding them to the website as soon as they are completed. They will be sold as a self-install Compression and Rebound knob kit, and will also retro fit almost all the production cartridges we have sold over the past 2 years. No risk of damage to the internals, we have made them so a broken knob will not compromise the internals, just remove the broken part and adjust with the original screw driver system.

-Does the top out spring on the actually get used when installed? Silly question maybe but it's hard to tell when it's all in the chassis. Just wondering if it's providing some or most of the top out force for the fork or if it comes mostly from the air spring side. I'd have to imagine that if I was running @140mm travel that the rebound piston assembly would never be touching the spring. Unless you ship a longer spring for that setup?

The top spring is only used in the 160 mm travel mode, we can space it to be specific for your travel setting or add a larger rate or length spring to help with top-out issues for some air side forks such as the 2013 Fox 34 with has top out issues when more than 85 psi are used. This also means the cartridge needs to be dissembled to change the travel in the future.

-Locally Maxima 85/150 is fairly easily available, but your recommended golden spectro and the others on the list aren't. Any thoughts on the maxima fluid?
Yes, Maxima 85/150 is an equivalent and will work fine.