Air spring re-lube with caution, especially pay attention to not overgreasing negative chamber, also bushings need to be checked - tight fitting or alignment issues may cause harshness.

 

Fox 38s are just not that plush unless you're riding really hard in heavy tech or you weigh a lot. I even got a Secus and it helps a little, but it's not transformative. The Fox 36 is much more plush and I prefer that for most trail/all mountain riding, while using the Fox 38 for fast, hard gnar.

 

The Grip2 forks are not very forgiving. I've had several. They are decent if you are pushing hard in chunky terrain, and are good when doing big drops and jumps. But on moderate trails it is hard to get them to feel all that good.

My DVO Diamond and Zeb Ultimate both feel so much better than my current Fox 36. I've done a lot of tuning - they just never feel that good.

 

Hmm, my 38 vvc feels plush but not much else to write home about.

My domain bound up so badly from bushings I assume, it probably had 15 pounds of breakaway force from sag.

Did you set the pinch bolt? Maybe you are hitting a wall of progression and could try fewer spacers with higher pressure? Sounds like you're probably aware of those options and it's not your issue, just making guesses.

 

Thanks for the feedbacks i can also confirm that pushing hard changes day to night. Let's see if someone has input on the oil effect.

 

Stiction is your problem. No you wont fix it with damper oil.

 

how to improve it ?

 

The oil in the right leg has to be the same as in the damper.
The oil in the left side should be sticky enough, so if not Fox 20gold it should be at least some kind of engine oil.

If there is not too much grease in the negative chamber, and if the foam rings are well soaked with oil, and the bushings are easily sliding (check those first!) - then it might be that the shimstack in the damper is off.

Or you just might like the eBike tune better, it is way softer (I run HSC 2 from closed - LSC 5, HSR 3, LSR 8). This worked fine for me on all the trails in Finale, from Ingegnere to Dolmen - I am not very fast.

 

The oil in the right leg has to be the same as in the damper.
The oil in the left side should be sticky enough, so if not Fox 20gold it should be at least some kind of engine oil.

It's actually 20W in the air side, 5W on the damper side - 2021-2025 38mm FLOAT NA2 Air Spring Rebuild | Bike Tech Help Center | FOX
Recommended 15-20% sag. - FORK- 2025 36mm/38mm | Bike Tech Help Center | FOX

Also recommend watching this for all Fox forks -

 

Did you properly deflate/reinflate the air spring in increments while cycling the fork up and down to equalize the negative chamber?

 

Mine came with 4 volume spacers, taking them out and getting rid of the gobs of grease in the air spring helped.

 

Get bushings burnished. I have done it on Pikes, 34, 36, Onyx and it made all the difference in the world. Most LBS will do for $40 if you bring them the fork.

 

run your compression and rebound on middle settings and adjust from there.

i am 200 lbs and i have to run compression about halfway and rebound about 2/3 closed and it works great.

whenever i run compression open and rebound close to closed, as I do on my GRIP and other forks, the fox 38 feels terrible. It requires more compression and less rebound and then it feels amazing. it was counter intuitive to me when i first got it.

mine is very supple. also make sure you have setup your axle correctly.

 

May I ask how much pressure do you run?
I'm on 190lbs dressed and on e-bike running 90psi with no token. Working almost all travel with no bottom out, no jumps mostly Enduro harsh terrains.

Meantime I've ordered the bullet tool to service the air spring , will check also bushing tolerance. Will keep you posted

 

I'm on 190lbs dressed and on e-bike running 90psi with no token

So an eBike tuned 38?

My 38 is eBike tuned (sticker on right crown), but no eBike.
200lbs geared, 110psi, one token. Without token I had some harsh landings.

 

Well IMO your air pressure and no tokens is your issue

As a comparison I run 112-114 psi and 2 tokens, we are the same weight and I’m on an SL ebike

Don’t chase suppleness with lower air pressure, the fox 38 air spring doesn’t like it

 

90psi is low. Transfer ports might be clogged by grease, preventing correct setting of the negative chamber. How long is the visible stanchion? Should be about 1cm more than nominal travel, no more. If you deflate the fork slowly with the button on the shock pump, does it stay up or it sinks?

 

Thats been mentioned a few times in this thread, but assume he’s missed it, as he’s ordered tools to service the fork?

Forget about the Fox 38 mega thread

https://www.mtbr.com/threads/fox-38-whats-your-setup.1151629/#replies

 

Ordered full service set and tooling. I'll try the skf dual compound will post results and finding. Thanks to all for the input and Suggestions

 

If all those efforts don't get it to perform as you want, then you might consider the new version Lift damper from MRP.

 

+1 for mrp V2 Lift.

I've got two buddies whom have gotten Fox to warranty the fork for this exact issue on new 38 gripX2. 1 dude said his new warranty fork was exactly the s ame, other fella is still waiting.

 

+1 for mrp V2 Lift.

I've got two buddies whom have gotten Fox to warranty the fork for this exact issue on new 38 gripX2. 1 dude said his new warranty fork was exactly the s ame, other fella is still waiting.

What was the issue they had? no compression? no rebound?

 

Damn this post resonates. Came here for this. Hope I'm not derailing but adding to the conversation!

I have a similar issue. It's hard to describe why I don't enjoy my 38 (2023 GRIP X / 170) but it just feels wrong. I haven't even enjoyed riding the bike that I built up with it. After a year of messing around with tokens / air and settings (I even got a coil for the rear because I thought it was the bike I wasn't getting along with) I threw a 36 on the bike and instantly felt comfortable. I even went back to the air shock and I now love the bike.

Regarding the fork - I never really trusted the front end. I can't say if It was harsh or what but I felt like couldn't get over it and ride the front of the bike. Played with stack / sag etc. It just never felt right. When I threw the 36 on it was like I was home. I will probably leave the 36 for local riding as I have a lot of technical climbing trails that are better on the 36 and fine on the DH.

For certain rides / trips (North to CA) I would like to have a 38.

So my options are :
1. Get a custom local service and ask the tech to do whatever to make it better (I trust his work).
2. Sell and get a new 38 with the new damper
3. Get a lyft v2 damper.

Thoughts?

Thanks.

 

Well. You got a tech who you trust. Why are you posting here and not talking to him?

If he is any good, he will have a look and tell you it is crooked or fix it. Probably has too much stiction and no new damper will fix it.

 

^^This. Solve friction problems first. Burnish that thing and its unlikely you'll even want those "upgrades" afterwards. Fox has a great air spring design on their 38's, I always find its best to run no volume spacers and use higher psi. Coil conversion is the next best move after reducing chassis friction to get rid of air spring friction.

 

So, today I could finally open the fork for servicing. After the service it runs much smoother. Just to complete the scenario below usage data:

• running time : 120h
• riding condition: muddy winter
• air spring coming from fox assembly line (never serviced)

Findings:

• both air spring and damper quite sticky
• air spring had huge amount a grease on the lower as reported from many
• damper oil viscosity was quite changed and colored
• bushing quite tight, but acceptable

Service actions done:

• full air spring rebuild
• oil change into damper (motul 2.5w)
• dust wiper changed with dual compound skf
• lower oil on spring side, supergliss 100k

 

Very nice. I think a lot of users would benefit from the service you just did to your Fox fork.

Fox makes great stuff, but their factory assembly is kinda shoddy and it's a darn shame because it really devalues their whole brand.

I've found that after a quick lowers service, and opening up that air spring and replacing all the assembly grease with a bit of Fox Gold 20wt, any Fox fork feels noticably better. I wish more people would do this more often.

 

I've owned a lot of forks from diff manufacturers over the last 30+ years and the Fox 38 grip 2 damper is the best one yet. They need to tighten up their assembly process to avoid these issues.

 

I went a bit further into experimenting attempting to improve sentitivity and reducing damping as I still had to run HSC, LCS , LSR full open for my personal taste.

Test 1: replacing the damper oil from Motorex 2,5wt (viscosity 14.5 cts @40°C) with Putoline HPX 2,5 wt (viscosity 6.67 cts @40°C).

• Sensibility improved quite significantly
• Damper in hand, the puloline feels less smooth than motorex even if damping is reduced
• Putloine is noisier on big hits

Test 2: in addition to the damper oil also replaced the supergliss 100k on spring lower against Motorex 2,5wt (both legs bath oil equal now)

• Sensibility improved again
• will test more extensively to see what happen heating up in summer
• my speculation is that bushing is still a bit tight and lubication with supergliss is not optimal in this case (some expert please comment)

 

I went a bit further into experimenting attempting to improve sentitivity and reducing damping as I still had to run HSC, LCS , LSR full open for my personal taste.

Test 1: replacing the damper oil from Motorex 2,5wt (viscosity 14.5 cts @40°C) with Putoline HPX 2,5 wt (viscosity 6.67 cts @40°C).

• Sensibility improved quite significantly
• Damper in hand, the puloline feels less smooth than motorex even if damping is reduced
• Putloine is noisier on big hits

Test 2: in addition to the damper oil also replaced the supergliss 100k on spring lower against Motorex 2,5wt (both legs bath oil equal now)

• Sensibility improved again
• will test more extensively to see what happen heating up in summer
• my speculation is that bushing is still a bit tight and lubication with supergliss is not optimal in this case (some expert please comment)

After testing the above setting this is what I can confirm:

• static friction massively improved
• I now need to run higher pressure from 90psi to 125psi getting same travel usage
• I'm finally able to use LSC HSC LSR that I now can run middle

CONCLUSION:

• Low viscosity in grip 2 damper helped
• motorex 2,5wt in both leg bath was game changer compared to supergliss 100k on the spring side

 

I have to share that i appreciate this thread tremendously. I am struggling with my 2024 Fox 38 170mm Grip 2. 2 volume spacers. 90 psi. 2024 Orbea Wild. I wanted to share about my call with Fox today. Because I have 2 Fox 38s and love the one that is on my 2022 38 Grip 2 170 mm 82 psi one volume spacer. 2022 Stumjumper Evo with Cascade link. 2022 is plush, awesome grip. 2024 is harsh even with 70 psi when all compression and rebuond are wide open. Fox said the 2024 has "the TML tune" and different bushings from my 2022. And they suggest 95 psi with 2 tokens and settings way firmer. I took it out today and tried their settings. Sucked. Harsh. No grip. Basically dangerous. Is there any way to make the 2024 feel awesome like the 2024? New damper cartridge with older or another tune? Fork has a couple hundred miles on the fork so burnishing wont help. Both forks and air springs have been recently serviced. Thanks all for insights and suggstions!

 

I put an MRP damper in mine and it really made it a LOT better. Then a smashpot which im still evaluating but also seems good. This is on an ebike so im nt worried about the weight too much . Focused on downhill

 

I put an MRP damper in mine and it really made it a LOT better. Then a smashpot which im still evaluating but also seems good. This is on an ebike so im nt worried about the weight too much . Focused on downhill

That's not necessarily the most economic option. A whole new damper off the bat.

Tried taking tokens out? I don't know the pressures off the top of my head, but the 38s I've ridden had a lot of compression damping. Are the dampers interchangeable between a 22 and 24?

Hey ya'll. Thank you all for jumping back in on this thread. I appreciate the feedback on burnishing. That may be next. So my 2024 fork has different bushings than the 2022. It also has "the LNT tune" or 'Lance's New Tune" according to the serial number when I called Fox service. They were super helpful. They explained that the mid valve support is increased. I did two things today. performed an spring service where I cleaned the grease from the head but did not remove the shaft and put a little 20wt back on the head. What I found when removing the air spring cylinder was there was a lot of 20wt oil in between the air spring cylinder and the stanchion wall. This could have been acting like a volume spacer. I also put 2.5 wt oil into the damper instead of the 5wt. Those two things combined just allowed me to put 95 psi in the air chamber and put the compression and rebound clickers in the middle and have the fork be waay less harsh. For some labor and $2 worth of 2.5 wt oil I think I need more testing but we are on the right track. Thoughts appreciated.
And again, thanks for the input. Anyone else have the LNT tune?