Fox 34 CSU creak?

S

SummitFever

Eats Squid
I think my Fox 34's are developing some CSU creak. Just today the bike has developing a ticking noise coming from the steerer area. It's amplified by the carbon frame and particularly noticeable when going slow over very bumpy ground. Have checked over the bars, stem, headset and frame, and they all check out OK.

Has anyone else experienced a ticking/clicking noise from the 2020 F34 CSU? Although this isn't the first Fox fork I have owned, it is the first that I have had the "pleasure" of riding, so I'm new to the whole creaking CSU thing.
 
link1896

link1896

Mr Greenfield
NFI about current fox 34’s creaking but I’ve fixed older fox that sounded like a whicker basket holding up a car.

Pull CSU out of forks, give it a general clean then dribble naphtha into the upside down stanchion/crown and the steerer junctions. Then blow out with compressed air and dribble loctite in.

Or offer your soul to the fox warranty gods? New bike you bought in Germany right?
 
  • Like
Reactions: Zaf
Litenbror

Litenbror

Eats Squid
I'm chasing a similar issue with mine at the moment, mine are a year and a half old not a few months though.

There are plenty of posts on mtbr forum about the issue but you should be able to warranty yours.

If you want to have a look at mine to see if the noise is the same give me a call.
 
Litenbror

Litenbror

Eats Squid
I started noticing a noise after crashing at Stromlo into a massive dust pile which I'm assuming got into the CSU. I'm going to try penetrating fluid to clean out the dust then Loctite since I'm out of warranty.
 
S

SummitFever

Eats Squid
Cheers guys. I'll probably pull the fork apart and see if I can identify where the clicking is coming from. If its actually the CSU then I might talk to the LBS about getting it warrantied. Its the fork from my Aussie bought Trance so local warranty shouldn't be a problem.
 
Litenbror

Litenbror

Eats Squid
Forgot to mention to check it was the CSU I stood facing the bike and locked the front wheel with my legs then twisted left and right on the bars. This took and forward backward loading out of play so it wasn't the headset and I could get close to the CSU to listen when doing it.
 
Oddjob

Oddjob

Merry fucking Xmas to you assholes
The Fox creaking CSU is a well known problem. It occurs to the stanchions and more worringly the steerer. Google nsmb and creaking steerer for some horror stories.

First port of call would be a warranty, second would be to get a Manitou Mattoc pro, its a much better fork especially with the irt spring.

Sent from my SM-G970F using Tapatalk
 
Nambra

Nambra

Definitely should have gone to specsavers
Litenbror said:
Really interesting article about it here

http://blueliquidlabs.com/suspension/article-two/
Click to expand...
Good read. So he's saying that it is corrosion in the interference fit that causes creaking, but you want some corrosion to occur for the best long-term creak-free results when fixed. I'm inclined to think that sealing the steerer / stanchion to CSU interfaces from new would also help, as it would prevent the creak-causing corrosion from occuring in the first place?

The article only mentions Loctite "retaining compound" of which there are a few - Loctite 648 looks like the optimum choice as it has low viscosity and high strength?
 
Litenbror

Litenbror

Eats Squid
Nambra said:
Good read. So he's saying that it is corrosion in the interference fit that causes creaking, but you want some corrosion to occur for the best long-term creak-free results when fixed. I'm inclined to think that sealing the steerer / stanchion to CSU interfaces from new would also help, as it would prevent the creak-causing corrosion from occuring in the first place?

The article only mentions Loctite "retaining compound" of which there are a few - Loctite 648 looks like the optimum choice as it has low viscosity and high strength?
Click to expand...
I took away that when they fit from the factory, due to the tight tolerance, there isn't enough retaining compound on the interface which allows the corrosion to occur. Older forks that aren't as tight anymore have a better coating of loctite after fixing so stay creak free longer.

I'm thinking there are actually a number of different issues getting lumped into the same basket because the symptoms sound the same. @SummitFevers forks are almost brand new so there is probably a lack of retaining compound which has allowed a small amount of corrosion to occur and hence to mild creak/cracking noise as discussed by the article above.
Mine on the other hand are a year and a half old and have been crashed into some pretty dusty stuff. This would lead me to think I have probably got dirt/dust into the interface which is causing a much more pronounced creaking noise. If this is the case it shouldn't be too deep into the interface so hopefully some cleaning and more loctite at the edge of the CSU Stanchion join will sort it out.

This is all hypothetical so take away what you will.
 
Nambra

Nambra

Definitely should have gone to specsavers
Litenbror said:
I took away that when they fit from the factory, due to the tight tolerance, there isn't enough retaining compound on the interface which allows the corrosion to occur. Older forks that aren't as tight anymore have a better coating of loctite after fixing so stay creak free longer.

I'm thinking there are actually a number of different issues getting lumped into the same basket because the symptoms sound the same. @SummitFevers forks are almost brand new so there is probably a lack of retaining compound which has allowed a small amount of corrosion to occur and hence to mild creak/cracking noise as discussed by the article above.
Mine on the other hand are a year and a half old and have been crashed into some pretty dusty stuff. This would lead me to think I have probably got dirt/dust into the interface which is causing a much more pronounced creaking noise. If this is the case it shouldn't be too deep into the interface so hopefully some cleaning and more loctite at the edge of the CSU Stanchion join will sort it out.

This is all hypothetical so take away what you will.
Click to expand...
Sounds logical to me - I was thinking that they didn't use retaining compound during manufacture, allowing oxidation to occur in the first place. Possibly they do though, and it just doesn't prevent corrosion.

I'm just pondering whether there is anything pre-emptive I can or should do to my 34's to keep them creak free. I wonder if there is any difference between Kashima coated forks and standard anodised ones as far as one type being prone to creaking more than the other?
 
S

SummitFever

Eats Squid
Interesting article @Litenbror . By not riding any Fox forks over the last 20 years, all of this creaking has passed me by, but you guys are right, there is a lot of complaining on the interwebs about it.

Shame there aren't any lightweight medium travel dual crown fork options. My gut tells me that it would be quite possible to build something in the 130-140mm 29er variety that would be stiff and a similar weight (as well as all of the benefits of dual crown like easy to replace inexpensive stanchions).
 
link1896

link1896

Mr Greenfield
SummitFever said:
Interesting article @Litenbror . By not riding any Fox forks over the last 20 years, all of this creaking has passed me by, but you guys are right, there is a lot of complaining on the interwebs about it.

Shame there aren't any lightweight medium travel dual crown fork options. My gut tells me that it would be quite possible to build something in the 130-140mm 29er variety that would be stiff and a similar weight (as well as all of the benefits of dual crown like easy to replace inexpensive stanchions).
Click to expand...
With 5mls of oil in each lower being a bridge too far for Rockshox at the assembly stage, your desire for serviceability and durability is so closely aligned with the two prevailing manufacturers I’m left wondering if you’re a sales rep for both. :)
 
S

SummitFever

Eats Squid
On the plus side, it will probably give me a chance to see how the Trance goes with my RTC3 Reba non-boost. Its 32mm stanchions and 100mm axle spacing will probably make the bike unrideable...
 
Last edited:
sane

sane

Likes Bikes and Dirt
I can’t believe this is still a thing. There was enough of a known issue in 2013 to replace 2 fox forks of mine under warranty without question. Could try harder
 
Oddjob

Oddjob

Merry fucking Xmas to you assholes
sane said:
I can’t believe this is still a thing. There was enough of a known issue in 2013 to replace 2 fox forks of mine under warranty without question. Could try harder
Click to expand...
Apparently it's due to the light pressings Fox do in order to keep the weight of the CSUs down.

Sent from my SM-G970F using Tapatalk
 
ozzybmx

ozzybmx

taking a shit with my boobs out
Had this on 3 Fox forks now, 1 x 32 (2015) and 2 x 34's from 2017/2018. My 36's I have now are the first Fox forks I've had since 2015 that don't creak.

Pull them off the bike completely, spin them upside down and clamp the steerer in a vice and wiggle the legs, it will become clear very quickly where the creak is coming from. Fox will replace them under warranty.

The wicking loctite works for a little while then back to creaking. Be careful with it as it strips the paint off the CSU.
 
You must log in or register to reply here.
Top