Fox 38 Harshness?

[Tedgar]

I have 38s on one bike and Lyrics on the other. Love the lyrics out of the box. To get the 38s to feel that good I removed one of those gray plastic tokens. I have 2 in it now. I keep compression open and adjust air pressure till it feels good. Don't care what sag is. Feels very plush, but they creak like an Amish horse drawn buggy.

 

[Gyre]

I have 38s on one bike and Lyrics on the other. Love the lyrics out of the box. To get the 38s to feel that good I removed one of those gray plastic tokens. I have 2 in it now. I keep compression open and adjust air pressure till it feels good. Don't care what sag is. Feels very plush, but they creak like an Amish horse drawn buggy.

I noticed the creaking as well. I was thinking to myself, “Even the 38 CSU/stanchion creaks?! Holy s**t!” Fox really needs to get their act together on that. I can’t remember my Lyrik or Zeb doing anything like that.

 

[Forever Wild]

I noticed the creaking as well. I was thinking to myself, “Even the 38 CSU/stanchion creaks?! Holy s**t!” Fox really needs to get their act together on that. I can’t remember my Lyrik or Zeb doing anything like that.

None of my RS forks creak. Yari, Lyric or Zeb.

 

[Pigin]

Apparently there’s a fix/bodge to stop the creaks.

 

[JW9]

To the OP, the harsh feel is likely that you have too many volume spacers in the fork for your type of riding. The fork is ramping up too much and this results in a harsh ride. The Fox 38E comes with one more spacer that the standard 38, to provide additional ramp and bottom out resistance for a heavy ebike, however in many cases it not needed. An ebike only weighs an extra 10kg over non ebike, A light rider on a ebike could weigh less than a heavy rider on a non ebike, yet the ebike still has a fork set up for a heavier load.

I had a similar experience when I first rode my 2021 Commencal Meta Power 29 signature with the Fox Factory 38E, 170mm. It felt harsh with the 3 spacers as installed from the factory. So I removed all 3 of the volume spacers and rode it on a few different trails to get a feel of the ramp and bottom out point. It was nice and smooth throughout the travel but bottomed out on the big landings. So I added one spacer, but still bottomed out a bit too easily, now I am on 2, however I think that 1.75 spacers is actually what I would like as the ramp up on 2 spacers feels a bit too much!

 

[Gyre]

To the OP, the harsh feel is likely that you have too many volume spacers in the fork for your type of riding. The fork is ramping up too much and this results in a harsh ride. The Fox 38E comes with one more spacer that the standard 38, to provide additional ramp and bottom out resistance for a heavy ebike, however in many cases it not needed. An ebike only weighs an extra 10kg over non ebike, A light rider on a ebike could weigh less than a heavy rider on a non ebike, yet the ebike still has a fork set up for a heavier load.

I had a similar experience when I first rode my 2021 Commencal Meta Power 29 signature with the Fox Factory 38E, 170mm. It felt harsh with the 3 spacers as installed from the factory. So I removed all 3 of the volume spacers and rode it on a few different trails to get a feel of the ramp and bottom out point. It was nice and smooth throughout the travel but bottomed out on the big landings. So I added one spacer, but still bottomed out a bit too easily, now I am on 2, however I think that 1.75 spacers is actually what I would like as the ramp up on 2 spacers feels a bit too much!

I'm a heavy rider (~100kg geared up), but I've generally run my forks with as few spacers as possible. According to Fox's documentation, my fork comes from the factory with four (!!) spacers. Definitely seems too much. I have air shaft servicing tools on the way and will take out some spacers as soon as I have the time to open it up.

 

[Cb750stu]

Good idea getting this tool for when you remove/ install the airshaft ?

FOX FLOAT NA 2 Bullet Sealhead to Shaft Tool

| Genuine OE parts

www.silverfish-uk.com

 

[Rob Rides EMTB]

Fair amount of grease at the bottom of mine. Not sure how much is correct without reading tech manual.

 

[pampmyride]

It's what's in the lower (negative?) chamber that's the issue.... Only a strip down will show you.

 

[Rob Rides EMTB]

Also @Gyre - the Fox 38 on Levo Gen 3 had 3 tokens from factory.

 

[Mteam]

Fair amount of grease at the bottom of mine. Not sure how much is correct without reading tech manual.

View attachment 59141

View attachment 59142

wrong chamber - need to look in the negative chamber for the excessive grease - the above photos are fine for the positive chamber

 

[Gyre]

Fair amount of grease at the bottom of mine. Not sure how much is correct without reading tech manual.

It’s supposed to be a “thin film” per Fox. As others have noted, the real trouble is when it eats up the negative air spring volume.

2021 38mm FLOAT NA2 Air Spring Rebuild | Bike Help Center | FOX (Step 13)

 

[RickBullotta]

To the OP, the harsh feel is likely that you have too many volume spacers in the fork for your type of riding. The fork is ramping up too much and this results in a harsh ride. The Fox 38E comes with one more spacer that the standard 38, to provide additional ramp and bottom out resistance for a heavy ebike, however in many cases it not needed. An ebike only weighs an extra 10kg over non ebike, A light rider on a ebike could weigh less than a heavy rider on a non ebike, yet the ebike still has a fork set up for a heavier load.

I had a similar experience when I first rode my 2021 Commencal Meta Power 29 signature with the Fox Factory 38E, 170mm. It felt harsh with the 3 spacers as installed from the factory. So I removed all 3 of the volume spacers and rode it on a few different trails to get a feel of the ramp and bottom out point. It was nice and smooth throughout the travel but bottomed out on the big landings. So I added one spacer, but still bottomed out a bit too easily, now I am on 2, however I think that 1.75 spacers is actually what I would like as the ramp up on 2 spacers feels a bit too much!

If you really think you can tell the difference, you could easily grind one of the spacers a bit, as long as you use it at the bottom of the stack. Just be sure to wash/blow off all of the grinding debris before installing it.

 

[Cb750stu]

It’s supposed to be a “thin film” per Fox. As others have noted, the real trouble is when it eats up the negative air spring volume.

2021 38mm FLOAT NA2 Air Spring Rebuild | Bike Help Center | FOX (Step 13)

In step 8 I was surprised how tight the foot stud was , I didn't want to heat it up due to possibly destroying the inner oring and I couldn't seem to be able to get spares at the time , definitely need 10mm shaft clamps or you would never get the footstud off ,
Also the retaining clip that holds the airside assembly in is a bit harder to remove this year compared with before so I'd recommend a fine pick to remove it ?

 

[RickBullotta]

In step 8 I was surprised how tight the foot stud was , I didn't want to heat it up due to possibly destroying the inner oring and I couldn't seem to be able to get spares at the time , definitely need 10mm shaft clamps or you would never get the footstud off ,
Also the retaining clip that holds the airside assembly in is a bit harder to remove this year compared with before so I'd recommend a fine pick to remove it ?

I remember rebuilding a Manitou XVert Super once and was surprised how tight the bolt that held the lowers on was - until I snapped it and realized it was reverse threaded. D'oh!

 

[pampmyride]

It's what's in the lower (negative?) chamber that's the issue.... Only a strip down will show you.

 

[JW9]

If you really think you can tell the difference, you could easily grind one of the spacers a bit, as long as you use it at the bottom of the stack. Just be sure to wash/blow off all of the grinding debris before installing it.

Thanks for the info, I'm actually fairly obsessed with suspension tuning so I can totally feel the difference. I have modified the Rockshox volume spacers on one of my other bikes methodically by drilling out the centre of the spacer increasing the drill bit size each time after each ride. I used two spacers, kept drilling one until i went too far, then went back a step on the other spacer. I'll probably do a similar process with the FOX at some point too.

 

[RickBullotta]

Thanks for the info, I'm actually fairly obsessed with suspension tuning so I can totally feel the difference. I have modified the Rockshox volume spacers on one of my other bikes methodically by drilling out the centre of the spacer increasing the drill bit size each time after each ride. I used two spacers, kept drilling one until i went too far, then went back a step on the other spacer. I'll probably do a similar process with the FOX at some point too.

I don’t doubt it. A perfectly tuned suspension is a wonderful thing!

However, there’s a potential solution with a fork cap that has a threaded shaft and disc with a seal that could provide precise adjustment.

or a coil spring.

 

[Forever Wild]

Definitely more harsh in my experience compared to Zeb. But that harshness also equals more feel of the trail too.

I wouldn’t say it’s too harsh, but definitely a lot of feeling is transferred to the rider. Vs the Zeb, nice and soft initial stroke in comparison.

I need to play around with rebound a bit more. But I still think it’s just going to feel not quite as supple as the Zeb after all the adjustments

I could not agree more. I set my pressure to factory recommendation on my new Fox Factory 36. I set rebound to factory recommendations and set my HSC and LSC wide open. Not too harsh but not as plush as my Zeb ultimate or Lyric Ultimate. It does feel solid and trail feedback is nice.

The bad.... first 15 feet of riding it as I’m coming down a steep embankment I heard one fairly loud “clack” sound. One hour into my first ride I heard my second “clack” sound as I’m descending a steep technical trail. I’ve never heard that sound from my Rockshox forks (Yari, Lyric, Zeb, Boxxer). Sounds like it’s coming from the stanchion. Doesn’t seem to affect performance. Just annoying really. Maybe not ideal for a heavy rider. Makes me appreciate my Rockshox forks. I abuse the hell out of them and they don’t ever give me negative feedback.

With all of that said. I don’t regret my purchase of the Fox 36 Factory. It’s sort of an experiment for me.

 

[Truckeemtb]

For what it's worth, probably not much... I have never gotten along well with Fox. I am 140 lbs or less. However, the new 38 on Gen3 Pro feels really really good. Still tweaking and only 1 week and 150 miles in. Previously if I ran lower air it would pack up in the mid stroke and would have to run super fast rebound and still never felt as good off the the top as Lyric or Pike Ultimate. Vorstrung helped a little but never felt great. I couldn't get even close to full travel out of a 36 even on medium large jump unless I fully cased a gap.
So now with new 38 I took out all 3 tokens. Almost full open LSC 14 or 15 (still playing) , 72 or 73 psi and I can use almost all off 5 foot drops (which is about all I do). Feels super stable and fairly push off the top, great and speed. The rest of the settings are within a few clicks to recommended. So overall happy. Still messing with final psi, HSC and Rebound.

 

[Careyj1]

A few weeks ago at a XC race, I talked with a Specialized Rep about setup on the Fox 38 on the 2022 Sworks Turbo Levo. The rep raced the same bike and won. The rep told me that he is finding that PSI for the fork should be 10 to 15 pounds less than the suspension calculator recommendations. The shock is about the same as the suspension calculator. I lowered my psi in the fork before the race and the bike handled every well.

 

[Truckeemtb]

Wait what, a XC race with a Fox 38 on an ebike? I think I am confused on many levels.

Anyway, yes, Fox gives very ballpark numbers as a baseline starting point. It really depends on preference and sag. Some like 15% and some 20%. I do run less PSI than baseline chart by 5 PSI, doing that does also change rebound and other variables. In general less air requires faster rebound etc etc. It also depends on volume spacers, terrain, riding style....

 

[1Nixxxo]

For all Lyrik and Fox 36 owners I STRONGLY recommend DSD Runt. I gave a proper test and it’s a perfect upgrade!
Now I’m considering jumping on Fox 38 and the only thing that’s stops me right now is the lack of Runt.

Considering Runt performance. It came with shims and small spring, so I re-shimed my Lyrik Ultimate 2021 according to manual and installed the Runt. Now I use 12 psi less, fork uses all travel without clank and wall of force (actually I never felt when I bottomed out, only noticed it by looking at the o-ring), forks rides higher, just a little bit plusher. It’s actually a new fork! My friend has the same setup, but his Lyrik was custom tuned by Diaz suspension, so his fork might have an edge over mine. Re-shimed damper works great, but now I feel it’s limits, so now I’m looking for a better damper. Grip2 is advertised as more compliant and controlled, so maybe I’ll give the Fox 38 a try, hoping that the Runt will become available in summer. Öhlins TTX Air shocks works better that the fork, so the Levo is still feel a bit unbalanced, but way better than with stock Lyrik Ultimate.
For reference: my weight is 120 kg geared, Turbo Levo 2021 alu, 62 psi pressure, 117 psi in the Runt, HSC/LSC open, slow rebound.
Hope it helps.

 

[1Nixxxo]

Thanks for the info, I'm actually fairly obsessed with suspension tuning so I can totally feel the difference. I have modified the Rockshox volume spacers on one of my other bikes methodically by drilling out the centre of the spacer increasing the drill bit size each time after each ride. I used two spacers, kept drilling one until i went too far, then went back a step on the other spacer. I'll probably do a similar process with the FOX at some point too.

If you go with Runt, all of tge described above can be be done with suspension pump. Plus you’ll have a bit better small bump sensitivity as a bonus. Actually I was pretty happy with my Lyrik before Runt, now I feel that I want more complicated damper as I can feel how it works)))
Might also try Vorsprung Secus in conjunction with Runt, but on new 36 or 38 fork.

 

[warby]

Fair amount of grease at the bottom of mine. Not sure how much is correct without reading tech manual.

View attachment 59141

View attachment 59142

You may find this video helpful -


Excess grease in the negative chamber takes up volume effectively
reducing the volume of the negative chamber, this causes the harsh feeling of the 38's

 

[ruppia]

You may find this video helpful -


Excess grease in the negative chamber takes up volume effectively
reducing the volume of the negative chamber, this causes the harsh feeling of the 38's

Thanks for your help. For those kind of operation you need nearly 500€ and a lot of skill.

Do you now if Fox gave a sort of warranty of this kind of problem ?

Luca

 

[Gyre]

Thanks for your help. For those kind of operation you need nearly 500€ and a lot of skill.

Eh? How the heck do you arrive at that number?

 

[ruppia]

Eh? How the heck do you arrive at that number?

If you follow Fox manuals, at the very beginnning there is a list of parts. Google it and find all the parts

Nearly 500, perhaps a little bit more.

 

[Gyre]

If you follow Fox manuals, at the very beginnning there is a list of parts. Google it and find all the parts

Nearly 500, perhaps a little bit more.

I don’t have time to look at it now but I can tell you that I have the tools to service my air shaft. They sure as heck didn’t cost $500USD much less 500Euro. Many of the tools are non-specialized things you already have if you’re going to do technical work on the bike.

 

[ruppia]

Trust you, but i only search for original fox parts, thats the clue i think

Luca