Fox Float CTD/RP23/RP3/RP2/DRCV

BoostValve only shocks

SSD Modification and HSB Adjustment System

Available Now!

Removal of Boost Valve and replaced with our speed sensitive shim stack(SSD)
and Converts CTD/ProPedal Lever to HSB compression adjustment System

The boost valve is a position sensitive valve that adds more compression as the shock compresses, this is good in theory for big hits
but a problem occurs when the shock encounters high speed curb style bumps deep in the stroke, this is when the boost valve is adding more compression
whereas the speed sensitive valve will relieve this compression and make the bump feel smoother and prevent the high speed hydraulic lock that the boost valve creates.
The boost valve is removed and replaced with a custom tuned speed sensitive shimmed valving stack to give you big bump absorption with high speed square edged plushness.

The stock Float shock has been designed for more of a platform feel, and the lever creates more or less pedal performance,
so this platform feel, created by the boost valve, requires more force to overcome the threshold of the boost valve.
In other words the shock does not compress easily over small bumps and provides better pedal performance.

The SSD/HSB conversion takes a different approach to the shock adjustment.

Descend/Pedal SSD/HSB low speed Threshold option

Our goal is to create a better descending version of this shock, so we concentrate on setting the valving(SSD) for the frame leverage and terrain and put the pedal platform(HSB) feel in the adjustment. This allows us to create a plusher, smoother feeling shock without the harshness that was created by the boost valve of the stock internals.

We use the existing lever system to provide adjustment to the modified internals, for the RP23 it now acts like a 4 position low speed threshold adjust system. The firmest position “on 3” will be used for pedaling or the firmest threshold. For the CTD it now acts like a 5 position low speed threshold adjust system. The "descend" will be the softest setting and the "trail" position will give you fine tuning with the 1, 2 3 adjust positions. The firmest position “climb” will be used for pedaling or the firmest threshold. We are creating multiple settings for trail/DH riding that allows for fine tuning of the low speed compression for that plusher DH feel. In other words, we are starting with the Trail 2/On 1 position as the standard setting rather than the Descend/Open position. All positions provide pedaling performance without sacrificing medium and high speed bump absorption because the HSB adjustment is independent of the main valving system.The firmer the position the more the low speed threshold is increased, this creates more low speed compression that can still blow-off at varying rates depending on the lever position. The Climb/On 3 position provides the best pedaling performance without sacrificing medium and high speed bump absorption because we isolate the main valving from the climb adjustment. In other words, it is no longer a lock-out design, but now the firmest low speed threshold position, that can still blow off on medium and larger hits.

Pedal only/Firmer SSD/HSB low speed Threshold option

We do offer the same service for a less active/firmer pedal feel. This SSD/HSB option offers firm high speed square edged feel but with a less noticeable low speed blow-off to provide better pedal performance in the trail and climb positions. Small bump performance will be compromised to provide a firmer low speed feel, this is only recommended when pedal performance is more important than small bump downhill plushness. Trail or cross country only, not recommended for descending. This option isrecommended for riders looking for that cross-country feel, you will have to sacrifice downhill performance for pedaling resistance, as the valving is not set-up for downhill performance, the valving is optimized for resisting pedal forces, all positions of adjustment are designed for pedaling.


Great news for Evolution and Performance non-BoostValve
Shock owners!
Available Now.

Click here for more details to order

We are pleased to announce our SSD/HSB conversion kit that makes your Evolution/Performance shock internally similar to the Factory CTD/Performance/RP23 BoostValve shocks. price $229.

Shown above is the SSD/HSB conversion kit for Evolution/Performance Non-BoostValve Shocks

The Evolution/Performance Non-BoostValve series shocks were not compatible with our SSD/HSB mods, as they have no low speed compression threshold adjustment circuit and no rebound valving to revalve.

Converts CTD lever to Firm setting(Climb), 3 Medium settings(Trail) and Soft setting(Descend) settings of HSB compression adjustment.
Converts ProPedal lever to 3 trail settings(on position) and one soft setting(off position) settings of HSB compression adjustment.

Technical discussion:

The low speed circuit is converted to our HSB system, this allows for a
increased low speed compression threshold that still blows off on small bumps
to create that small bump plushness without the harsh feel.

The HSB also provides for a smooth transition of low speed compression
to the main piston valving shim stack.

High and mid speed compression system is controlled by the custom valved speed sensitive shimmed compression main piston. This is set-up to match the leverage and rider terrain.

Check valve systems are optimized to prevent the compression and rebound adjustments from affecting each others, thereby isolating the adjustments to a independent feel.

Mid and high speed rebound is controlled by a custom valved shim stack to match the riders weight
(air can pressure) and the leverage of the frame.
Low speed rebound can now be fine tuned by the red rebound knob,
i.e. more usable positions rather than coarse tuning for air pressure.

Includes custom revalve and setup for rider, frame leverage and conditions

and printed set-up chart.

We will recommend the air can size and air can spacer if needed

Optional ABS(anti-bottoming system) available for more aggressive and bigger riders or smaller riders on regressive linkage frame.

Also includes complete rebuild service, oil, nitrogen charge and typical wear parts* included in price.

New lower friction, higher temperature shaft seal and IFP seal, and more reliable IFP charging puck.

*(Typical wear parts: shaft seal, reducer DU bushings, and o-rings)

**The shock must be in good working condition with no scratches or dents on moving parts, if the air can is leaking, it should also be noted that air side will not be modified in anyway and any air side issues will not be addressed.

(Air can rebuild parts and volume spacers not included, these will be billed seperately if needed)
(Service interval will remain the same as before the modifications)


Typical Float CTD SSD Modified Shaft Piston Assy

Float Performance Series BoostValve CTD

FAQ's Here




Fox Float CTD/RP23/RP3/RP2/DRCV

SSD Modification
HSB Adjustment System

Shock must be sent in to receive modifications.

Price $199

Order Here and Send Shock for Modifications

Questions as to what affects how we set-up the shock, these generalizations hold true:
The compression valving is based on the leverage and type of riding, and rider ability affects this slightly. The HSB is based on your percentage of climbing and descending as well as the bikes ability to pedal or initial leverage. The rebound is based on the pressure in the air can (your weight) and the type terrain. Sag is set by the air can pressure. The overall spring rate is determined by the air can size and the volume spacers.

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 shock model that the SSD kit will be installed in.

Shock Model

Choose your SSD/HSB threshold tune option the kit will be set-up with.

Threshold tune

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 30% sag.
We need this number to help set-up your shock rebound damping correctly.

Click here for sag setting Tips

Air Pressure

We will help you choose your air pressure if you are unable to.
Service should be performed every 100 hrs, same as Fox recommends. For high leverage frames
or heavier riders requiring sag pressures over 185 psi, you should be aware that the
service life of damper oil will be dramatically decreased.

Choose your rider ability for us to set-up your shock.

Rider Ability

Provide us with Bike info to set-up your shock.




Provide us with any other info to help us set-up your shock.

Set-up Info





Air Can Rebuild Kit
optional service


Air can and air sleeve
Rebuild and and seal replacement


After 50 hrs of riding the air can seals and air sleeve piston seals need replacing and if not replaced periodically
this allows the internal air pressureto leak between the positive and negative chambers reducing the effectiveness of the air spring system.
The air can seals also become jammed up with dirtand mud which can cause damage to the air piston shaft and create a leak path for the air can pressure.

We may suggest you replace the stock seals when we inspect your internals or
make plans to replace them yourself to prevent these issues!
This does not include damaged or dented air cans or air piston shafts, seals only.

Shocks newer than 50 hours need only be cleaned and reassembled typically.

Add option here

Price $29.95 includes parts and labor


Air Can Rebuild

Price $29.95