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Fox "custom tune" codes

186K views 129 replies 70 participants last post by  bmwpowere36m3  
#1 ·
Does anyone know what these Fox abbreviations mean? I just bought a '17 Kona Hei Hei Trail. The code on the DPS shock is C9T4; when I plug it into Fox's website, I get this:

"2017, FLOAT DPS, P-S, A, 3pos, Trunnion SV, Kona, Hei Hei Trail, 165, 45, 0.6 Spacer, CM, RF, Climb F, Standard Logo"

Not sure what some of these mean--

P-S (?)
A (?)
3pos (3 positions of low-speed compression damping?)
Trunnion SV (trunnion mount, standard volume?)
165 (eye to eye?)
45 (stroke?)
0.6 Spacer (volume reducer, .6 cubic inches?)
CM (compression medium?)
RF (rebound firm?)
Climb F (low-speed compression firm?)
 
#2 ·
I have this info saved

Fox Tune Code info

https://www.cogentindustries.co.za/deciphering-fox-shock-information/

In the above picture we can see the ID being C372. Once you have this code you can head over to the FOX website and enter the information on this page: https://www.ridefox.com/help.php?m=bike

The page will list information regarding the specific code, the above shock gives us:

2017, FLOAT DPS, F-S, K, 3pos-Adj Evol SV, FOX, AM, 7.875, 2.0, CL, RM, Climb F, Orange Logo

Fantastic but what does this all mean? Let's break down the info, some of it more obvious than others:

2017: Year of manufacture
FLOAT DPS: Model
F-S: Factory Series
K: Kashima Coating
3pos-Adj Evol SV: 3 Postion Adjuster, Evolution air chamber with Standard Volume/Eyelet
FOX: Manufacturer
AM: After Market i.e. not OEM/Stock with a bike
7.875: Eye to eye length in inches
2.0: Stroke length in inches
CL: Compression Light
RM: Rebound Medium
Climb F: Climb Mode Firm Lock Out
Orange Logo: Decal Color
Now that we know what the codes mean let's explore some of them a little further.

F-S: Factory Series
Other options could include E-S - Evolution Series, P-S - Performance Series. This is the spec of your shock model and they each have different features such as more refined tuning on the high-end models and Kashima coating as listed above on the Factory Series.

3pos-Adj Evol SV: 3 Position Adjuster, Evolution air chamber with Standard Volume/Eyelet
Lever actuated Open, Medium, Firm modes. Open mode adjust tuning range (1, 2, 3) on the Factory Series as above.
Other options are Remote actuated Open, Medium, Firm modes or iRD electronic activation.

Evolution air chamber is an optional air sleeve upgrade that improves responsiveness and sensitivity.

SV refers to the air chamber size and eyelet size. Other configurations could be LV - Large or XV - Extra Large. This is important when upgrading and builds as the shock might not fit in your frame and cause issues under compression. For more information on this visit this page on the FOX website.

The last three codes we are covering can get very detailed and deserves a post of their own which we will cover at some stage. Herewith a short explanation of each.

CL: Compression Light
This refers to the level of compression damping of the shock so "L" is light compression. You will need to consider your type of riding as well as frame leverage ratios and take this into consideration. Other options are M - Medium, F - Firm.

RM: Rebound Medium
This refers to the level of rebound of the shock so "M" is medium rebound. You will need to consider your type of riding as well as frame leverage ratios and take this into consideration. Other options are L - Light, F - Firm.

Climb F: Climb Mode Firm
When you are in your firm mode on the adjustment lever or lock out as it is also known this will give you a firm feel with the least amount of pedal-bob. Other options are L - Light, M - Medium.

Shock tunes are set from the factory for the manufacturers frame and leverage ratios to cover as many bases as possible. The settings are predetermined to allow for lighter riders and heavier riders to get a good base setting that would let them enjoy riding. The range is set to cover a wide range of riders. If you get to the point where you feel you need fine control over a certain aspect of your suspension, it's generally accepted you know what you're missing from the basic setup. Then you get into custom tuning.

One way of finding the right match for your bike or frame is to get the original shock spec and tune id and looking at something that matches up with that.

Suspensions are all different and can get quite technical and there is a lot more detailed information that we can go into when it comes to some of the above parts of the code but we will leave that for future articles.

Sent from my iPhone using Tapatalk
 
#5 ·
I have this info saved

Fox Tune Code info

https://www.cogentindustries.co.za/deciphering-fox-shock-information/

Sent from my iPhone using Tapatalk
The few bits that haven't been answered.

A = anodised (i.e. not Kashima).
Climb F is your lockout blowoff with the compression adjuster set firmest.

These shocks have a three position lever where the first position allows free bleed around the shims, second position shuts that freebleed and third position shuts off flow to the compression shims. Leaving the lockout blowoff shims only active.
BRILLIANT--thanks!

For others--I also found a helpful animated video from Fox that shows the oil path:

Is my interpretation right that the shock has a .6" spacer installed? Might try it without the spacer and see how it acts, I'm a lightweight.

What is "dual piston" here--besides the damper piston, is the body of the damper (compressing the air spring chamber) the second piston?

In the video, it looks like the climb lever's middle position affects the high-speed oil path at least as much as it affects the low-speed oil path--is that true?

The video doesn't show how the rebound knob works--does it change the size of the orifice on the left side of the shaft (next to a red flow arrow) in this image?



Thanks again!
 
#3 ·
The few bits that haven't been answered.

A = anodised (i.e. not Kashima).
Climb F is your lockout blowoff with the compression adjuster set firmest.

These shocks have a three position lever where the first position allows free bleed around the shims, second position shuts that freebleed and third position shuts off flow to the compression shims. Leaving the lockout blowoff shims only active.
 
#6 ·
The dual piston is effectively 2 damping pistons on top of each other, so your high speed compression is separate to the lockout/climb mode. The lockout lever closes the freebleed down the centre of the shaft by shifting the necked down section of the metering rod into the shaft. The lockout plate gets closer to the piston but not enough to restrict flow. Once it touches down oil is forced through the lockout shims before the main damping shims.

Rebound is advancing the rounded part of the light grey shaft around the lockout metering rod in to the piston bolt to create a bigger or smaller orifice



Cla001 and rla 018 are the codes for linear compression and rebound tunes, most of the stock tunes are preloaded or digressive (even the ones that aren't identified as such)

Have quite deciphered the AFM part yet, refers to the compression piston in the ,rezi, so I guess it is a firm climb mode and medium HS compression tune
 
#7 ·
Anyone have a Rosetta Stone for deciphering the Tune Codes from Fox? The link above is helpful but seems like they have change some nomenclature/ abbreviations since it was posted.

Like this code for the Stumpy:
2019, FLOAT DPX2, F-S, K, 3pos-Adj, Evol LCR, Specialized, Stumpjumper 29, 210, 50, 1.0 Spacer, CM, DRL, Rezi A F M+, Neutral Logo, N/M

For the most part I think I can break it down but there are a couple acronyms that don't make sense:
2019, FLOAT DPX2 = product
F-S, K = Factory Series w/ Kashima
3pos-Adj = Compression Adjust (high speed)
Evol LCR = This is the air can size?
Specialized, Stumpjumper 29 = bike make and model
210, 50, 1.0 Spacer = shock size & volume reducer size
CM = Compression medium
DRL = Digressive Rebound Low
Rezi A F M+ = ?
Neutral Logo
N/M

From this link https://www.ridefox.com/fox17/help.php?m=bike&id=854 I found out that the AFM+ is the valve stack, but not sure what that means or what Rezi is.

I've called Fox but so far haven't made contact with anyone very helpful.
 
#22 ·
3pos-Adj = Compression Adjust (high speed)
Evol LCR = This is the air can size?
Specialized, Stumpjumper 29 = bike make and model
210, 50, 1.0 Spacer = shock size & volume reducer size
CM = Compression medium
DRL = Digressive Rebound Low
Rezi A F M+ = ?
  • 3pos-adj is NOT high speed. It indicates the shock has the 3 position Open/Medium/Firm low-speed lever and the open-mode has an adjustment.
  • Evol LCR is a Low Compression Ratio air can only for metric 210x50/52.5/55 shocks. I've only seen it on shocks tuned for 2019/2020 Specialized Stumpjumpers
  • CM & DRL (Light, not Low, on Fox's parts lists) are the high-speed stacks on the main-piston/mid-valve.
  • Rezi AFM+ is the base-valve at the top of the reservoir (rezi) and is connected to the 3pos-adj option: A = open mode is adjustable, F = firm low-speed compression in medium mode, M+= Firm/lockout mode blow-off threshold. On a shock without open-mode adjust, it would be "Rezi MFM+" or similar, and with a 2pos lever it would read "Rezi FM+" or similar.
 
#11 ·
Help with 2019 Fox DPS Tune Codes

Hi, help with deciphering Fox tune code for 2019 DPS OE rear shock on a YT Jeffsy AL 27.

2019, FLOAT DPS, P-S, A, 3pos, Evol LV, YT, Jeffsy 27.5", 230, 60, 0.2 Spacer, DCM, DRM, CML, Standard Logo

I think i understand most of these codes from reading about them in this thread but the ones i cant seem to get any additional info on is Digressive Compression Medium (DCM), Digressive Rebound Medium (DRM). re these designations referring to the shim stack configuration and its resulting tune?

Im asking this b/c im a larger rider. So far ive replaced the OE .20 spacer with a .60 spacer and higher psi which has improved the shocks bottom end but id like something thats more linear and improves the mid stroke since thats where i ride most the time. TIA
 
#12 ·
Hi, help with deciphering Fox tune code for 2019 DPS OE rear shock on a YT Jeffsy AL 27.

2019, FLOAT DPS, P-S, A, 3pos, Evol LV, YT, Jeffsy 27.5", 230, 60, 0.2 Spacer, DCM, DRM, CML, Standard Logo

I think i understand most of these codes from reading about them in this thread but the ones i cant seem to get any additional info on is Digressive Compression Medium (DCM), Digressive Rebound Medium (DRM). re these designations referring to the shim stack configuration and its resulting tune?

Im asking this b/c im a larger rider. So far ive replaced the OE .20 spacer with a .60 spacer and higher psi which has improved the shocks bottom end but id like something thats more linear and improves the mid stroke since thats where i ride most the time. TIA
Digressive stacks are preloaded. So they have more low speed damping and comparatively less high speed damping.
 
#14 ·
i could use the LCM and LRM valve sub assemblies, and use the CML assembly that came with the shock? Since i already have a positive spacer will negative spacers help get me where id like to go with this?
The linear should ride better and not break shims.

I have had those assemblies on order and not yet arrived. Have you got them?
 
#21 ·
I was curious about the tune i got on my DPX2, since i new its 'of the shelf' version my LBS got for my Bronson from Fox, so i checked the Custom Tune ID label on Fox site and this is what i got -
2018, SAMPLE, FLOAT DPX2, P-Se, A, 3pos-Adj Evol LV, FOX, ENG, 210, 55, CM, RM, Rezi A F F, No Logo, N/M

2018 - year
Sample - ?
Float DPX2 - model
P-Se - Performance Series Elite
A - 'black' coating
3pos-Adj Evol LV - 3 position adjustment, Extra Vol, Large Volume
FOX - ?
ENG - ?
210, 55 - size
CM - compression medium
RM - reverb medium
Rezi A F F - ?
N\M - ?

Most of it i understand, and for the rest i hope someone here can help with... :)
 
#27 ·
Does anyone know if the DPX2 base valve assembly can be tuned, eg. to increase the firm/"lockout" mode from "medium" to "firm" threshold compression setting for example?

Would a valve where climbing mode is configured to firmest setting have a smaller "firm mode port" hole than a valve with let's say medium setting? Or is this done simply by changing the reed valve configuration?

 
#28 ·
Does anyone know if the DPX2 base valve assembly can be tuned, eg. to increase the firm/"lockout" mode from "medium" to "firm" threshold compression setting for example?

Would a valve where climbing mode is configured to firmest setting have a smaller "firm mode port" hole than a valve with let's say medium setting? Or is this done simply by changing the reed valve configuration?

View attachment 1293905
Fox does sell different base valves for different compression configurations. You can find them here https://www.ridefox.com/fox17/help.php?m=bike&id=854

As far as modifying the one you already have, you could change the port selector, port size, valve or a combination of those. I haven't seen any base valves taken apart to be able to tell you how fox does it but someone else might chime in
 
#29 ·
Edit: I've already purchased the fox factory and insite would still be appreciated though.

Hello I have this frame https://www.lightcarbon.com/all-new-lightcarbon-trail-mtb-frame-lcfs958_p118.html

Currently I have a fox performance 165x45 off a Kona hei hei trail.

It does ok but I am looking at this https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/401768985488

It has this tune

2019, FLOAT DPS, F-S, K, 3pos-Adj, Trunnion, Evol SV, Evil, The Following, 165, 45, DCL, DRM, CML, Neutral Logo

I was going to see how it works and if it doesn't do well I would send it to Avalanche for tuning.

Part of my reasoning is I need a second shock so can have the other sent for service when needed

Second from the info I've gathered here this shock would have good pedal platform which a low single pivot flexstay bike would need I think.

But I am 145lbs and don't need as much compression so that's why I think it would work.

Here is the tune for my current shock

2017, FLOAT DPS, P-S, A, 3pos, Trunnion SV, Kona, Hei Hei Trail, 165, 45, 0.6 Spacer, CM, RF, Climb F, Standard Logo
 
#34 ·
Great info in here, thanks everyone! How about these 2 shocks

Shock 1: 2019, FLOAT DPX2, P-Se, A, 3pos-Adj, Evol LV, Forbidden, Druid, 210, 55, 0.2 Spacer, CEC001, RLA014, Rezi A F M+, Standard Logo

Shock 2: 2019, FLOAT DPX2, P-S, A, 3pos, Evol LV, Ibis, Ripmo, 210, 55, 0.4 Spacer, CEC001, RLA014, Rezi L F M, Standard Logo

I'm looking to place shock 1 on an Ibis Ripmo, which comes with shock 2's specs. Everything looks the same except for:
- Spacer 0.2 vs 0.4 - that's a variable anyway depending on rider weight and style?
- Rezi AFM+ vs LFM - I can't figure out what this means and how much it matters?

I'm in no rush so I'll probably skip shock1 but I'd be curious to know what others think.

Edit: Also what do CEC and RLA mean?

edit2: I'll throw shock 3 into the mix: 2019, FLOAT DPX2, F-S, K, 3pos-Adj, Evol LV, FOX, AM, 210, 55, 0.2 Spacer, CM, DRM, Rezi A F M+, Orange Logo - sounds like this is an aftermarket version - would it be a good generic choice as a replacement for Shock 2?
 
#35 ·
- Yes the spacers are a preference, but they also may be preinstalled by the bike manufacturer to suit the frame's suspension

- Rezi *** I believe refers to the low-speed compression tune at each position of the "climb switch". For AFM+, that's a 3-pos-adj model with the following tunes: Open position is Adjustable damping, Medium position is Firm damping, Firm position is Medium "lockout". LFM would be the 3-pos non-adjustable model, with a Low damping tune on the Open position. LFM is likely the same as the AFM+ with 0-2 clicks (from open, 9-11 from closed) of low-speed compression with the 3mm adjuster.

- CEC and RLA are [semi-custom] shim stacks, that I think come from common requests from suspension designers. You can actually see the exact shim stacks at https://www.ridefox.com/fox17/help.php?m=bike&id=1031. The RLAs seem to be linear, though RLA019 looks similar to the digressive ones. CEC001 seems to be a Linear Medium-ish, while CLA001 looks like it might be kind of a Digressive Medium-Plus.

- The third shock, with the DRM (Digressive Rebound Medium) tune, might not have the correct amount of rebound damping at certain parts of the stroke when used on a frame designed around an RLA or other tune. "Might" being the key word. You may not notice anything, or you may absolutely hate it.
 
#41 ·
It's funny because Rockshox has been doing pretty basic L/L M/L M/M tunes for awhile. Occasionally you'll se a custom tune code, but its pretty straight forward for them.

Meanwhile Fox is over here really getting into custom tunes for manufactures, which is a good thing.

I wonder if you could go to Fox (*via their FFT service) and say "here's my bike, my weight, my riding style - what tunes are already out there that are close to what I'd need?"

For all you know, some common bikes already runs the tune ideal for your weight and riding style. Or at the very least they can extrapolate based on the manufacturers spec, then add your weight into the mix.
 
#45 ·
What does it mean if there are tuning parameters left out?

Hi,

I typed in the four-letter code on my Float X2 into that site linked to earlier in this thread and it came back with this...

2020_19, FLOAT X2, F-S, K, 2pos-Adj, SBC Enduro, Fox AM, 8.5, 2.25, 0.3 Spacer x2, CM, Orange, Gray Logo

The CM means "Compression Medium", but there are no codes for the other factors of the tune like the rebound, DRM, climb mode, etc.

What are the aspects of the tuning parameters if Fox doesn't list them in that coded description???
 
#46 ·
Hi,

I typed in the four-letter code on my Float X2 into that site linked to earlier in this thread and it came back with this...

2020_19, FLOAT X2, F-S, K, 2pos-Adj, SBC Enduro, Fox AM, 8.5, 2.25, 0.3 Spacer x2, CM, Orange, Gray Logo

The CM means "Compression Medium", but there are no codes for the other factors of the tune like the rebound, DRM, climb mode, etc.

What are the aspects of the tuning parameters if Fox doesn't list them in that coded description???
The CM is the tune on the main piston. Other than that all X2's are the same.
 
#49 ·
Basevalve 3? No idea what that means. Here are the other options for context. Wonder how it compares to compression Medium?

815-02-197-KIT Service Set: Damping Adj Assy: 2021 DHX2 / FX2, Comp Base Valve, LSC Only
815-02-225-KIT Service Set: Damping Adj Assy: 2021 DHX2 / FX2, Comp Base Valve, LSC Only, CM
815-02-223-KIT Service Set: Damping Adj Assy: 2021 DHX2 / FX2, Comp Base Valve, LSC, HSC, CM
815-02-224-KIT Service Set: Damping Adj Assy: 2021 DHX2 / FX2, Comp Base Valve, LSC, HSC, BV3
 
#50 ·
I'm looking at buying a new (different/used?) DPX2 to replace the base-model one on my FS bike. The bike suspension curve is modestly progressive, and as far as I can tell, the tune is Light digressive to make things linear. The problem is, I'm blowing through travel too fast despite running max volume spacers and less than 25% sag.
Can any of the suspension gurus help me ID the differences in tune as highlighted below:
1915319


CL is compression Light tune; what is CAL001??
DRXL is digressive rebound, Xtra-lite. What is RLA014?

I've looked at the shim stack exploded views, but am not smart enough to understand what changes it would make.

I'm looking for *more progressive than I currently have.
 
#51 ·
You can sometimes guesstimate what the custom stacks do by comparing them to others.

RLA014 looks a whole lot like Linear Rebound Medium, but smaller shims at the bottom of the stack might make it slightly softer at high shaft speeds.

CLA001 looks a whole lot like Compression Medium, but but smaller shims at the bottom of the stack might make it slightly softer at at high shaft speeds.