Fox 40 Float/RC2/RC/R/Performance
Cartridge and Adaptor Kit




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

Complete replacement of the damper with our 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 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.

Semi-sealed cartridge and open bath ABS system for better lubrication and to minimize oil volume.

Smart Adjust Threshold Compression Damping System ™
Removes harshness out of firmer low speed compression settings.
Allows you to add compression for a firmer ride and auto adjusts for higher speed hits.
Optional user reconfigurable for progressive, linear and regressive threshold settings.

User serviceable, uses auto volume pressure spring system, no bladder or nitrogen charging required.
For details click here:

Cartridge ships with the internal damper oil already installed. (Spectro 85/150)

External low speed compression and rebound adjusters, Internal revalvable custom high speed compression and rebound valving, threshold reconfigurable.

Internal Anti-dive MidValving with optional shim kit for custom tuning.

Includes the 20 mm Cartridge Damper Kit Insert, ABS cone/lower casting adaptor, adaptor arbor sealing nut, oil lock adaptor ring
and oil lock snap ring.

Self install kit includes custom valving, and MidValves.

Optional Pressure springs Soft, Hard, and Regressive available

Optional Smart Adjust Progressive, Linear, and Regressive systems available.

Weight 450 grams (Fox Fit Cart 314 grams) filled with oil.

Fits all Fox 40 Float/RC2 Fit/RC2/R Models.


• 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 low speed compression
• Base valve adjuster screw with 22 clicks of low speed rebound adjustment
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 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
• Optional revalving kit for compression and rebound pistons, with revalving set-up charts
• Optional HSB compression blow-off system for the firmer feel with-out harshness
• Designed to be self-installed or send it to us for installation if you need us to do the install

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

Need us to install it for you, just send your fork to us and we will install it for $100 including Spectro 85/150 oil.

Buy an older version or the 40R fork and install the our cartridge.

You end up with a new Fox 40 with our better performing cartridge.



Images of Cartridge Installed

New Blue Adjuster for Low Speed Compression






Purchase Here

out of stock

Download: Fox 40 Cartridge Installation, Assy and rebuild and Set-up Manual Rev A(47.4 MB)

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

Fox 40 Float/RC2/RC/R/Performance
Cartridge Kit including Adaptor

and Midvalves installed, $599



Fox 40 FLOAT/RC2/RC/R/Performance

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 $100 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 model that the cartridge will be installed in.

Fork Model

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




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 $100



Price $100, plus shipping difference






The Avalanche Advantage over the RC2 FIT/RC2/RC/R cartridge:

Uses a pressure spring system to maintain proper minimum preload charge on the damper oil, this prevents cavitation(vapor bubbles that disrupt the damping feel).

Pressure spring system provides a linear feel to damper rod stroke, as compared to air charged and bladder systems, the rate can be changed up or down with optional pressure springs.

A larger (20mm vs 15.5mm) 4 port rebound valve that has more low to midspeed transition control and optional high speed shim configurations for different spring rates and rider conditions.

A midvalve with user tunable shims/valving that provides anti-dive feature while still blowing off without low speed harshness on small bumps.

The same DHF proven design (21.2 mm) 4 port compression valve with optional revalving charts and shims available to fine tune your fork for your individual riding conditions and ability.

End of travel position sensitive Anti-Bottoming system uses the outer slider tube and lower casting to take the load of the big hits,

as compared to the Fox dampers, the internal cartridge tube and rod of the damper are not spared from the stress and strain of these loads.

User serviceable, all parts are available here at Avalanche to service or modify the internal set-up. Oil is filled though the top of cartridge and self setting with one compression stroke.

Revalving kits can be purchased from Avalanche or any suspension tuning shop that carries standard 6 mm shims.

The inverted design prevents that blown, no rebound damping feel that you would get from the original RC2/RC/R damper when the bladder failed.

High speed adjustment is at best a compromise of the original shim stack, depending on the high speed spring preload adjuster rate and where the pressure is applied

on the shim stacks you can get less than desirable results in damping feel, i.e. preloading the outside rim of the shim may make the high speed stiffer,

but also creates mid and low speed harshness in the damper.

The original R2/RC/R large compression adjuster protrusion at the bottom of the fork is eliminated and cleanly redesigned and moved to the top for easy access.