Fox 38 Knocking sound

Simonp3

Member
Aug 21, 2020
32
9
Denmark
Not headstock bearings loose ?
Nope. Tried tightening the headset like, a lot. Also slightly over tightened the wheel axle. Nothing helped. When I hold my hand on the black outer legs, I can feel the knocking on the inside of the fork.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,674
8,946
Lincolnshire, UK
Talk to Fox, or whoever you bought the forks from. It is always unwise to ride a bike with a new or odd noise until you have found out what it is. It may be nothing, but it could be something. :unsure: :eek:
 

Christurbo

Well-known member
Jul 11, 2023
380
715
North Wales
If this was me (and its not) I would:-

Remove fork from frame.
-Service headset (or even replace)
-Lower leg service on the shock, torque lower bolts to factory spec
-Refit headset and grease
-refit fork

Ride.... I bet this will fix your issue as it will cover a number of variables.

There is a known issue where the stanchion meet the crown where some forks start to creak (not knock), preventive maintenance for this is to work some Loctite into the seal with fork upside down and wait until it sets. This is what Fox do (but they obviously remove the stanchions to add the Loctite).
 

Spin

Active member
Dec 24, 2021
181
228
Australia
If this was me (and its not) I would:-

Remove fork from frame.
-Service headset (or even replace)
-Lower leg service on the shock, torque lower bolts to factory spec
-Refit headset and grease
-refit fork

Ride.... I bet this will fix your issue as it will cover a number of variables.

There is a known issue where the stanchion meet the crown where some forks start to creak (not knock), preventive maintenance for this is to work some Loctite into the seal with fork upside down and wait until it sets. This is what Fox do (but they obviously remove the stanchions to add the Loctite).
If this was me , the bike ridden 20kms ? Straight back to the shop!
If it is something internal in the fork , that's clearly poor QA and should not be the buyers problem.
 

InRustWeTrust

E*POWAH Master
Mar 9, 2020
515
756
Sweden
If this was me , the bike ridden 20kms ? Straight back to the shop!
If it is something internal in the fork , that's clearly poor QA and should not be the buyers problem.

I agree here , if the fork is new it should go back to the shop asap. If you open up the fork maybe the shop denies to give you a new one so dont open it.
 

wenna

Member
Aug 1, 2023
209
141
Sweden
If not the headset or wheel, it sounds like play in the fork bushings to me.

Do you get the same play with the wheel straight and using front brake to rock it forwards and backwards?
 

Simonp3

Member
Aug 21, 2020
32
9
Denmark
If not the headset or wheel, it sounds like play in the fork bushings to me.

Do you get the same play with the wheel straight and using front brake to rock it forwards and backwards?
I only get play, when I turn the fork 90 degrees. I disassembled the headset and greased it up, I also tried without the brake caliper. It is definitely the fork..
 

Simonp3

Member
Aug 21, 2020
32
9
Denmark
It's not your problem, it's the shop's problem. Do not open the fork, just do as said above, take the fork back to the shop.
Only problem is that I bought it online, so it's quite a hassle, but I have contacted Fox, and the online shop.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,220
2,157
Chichester, W.Sussex, UK
Only problem is that I bought it online, so it's quite a hassle, but I have contacted Fox, and the online shop.
If you bought it online you will have EU distance selling laws to protect your purchase, also credit card protection. The forks are defective so get a refund and start again. The longer you leave it the potentially messier everything gets.
 

Simonp3

Member
Aug 21, 2020
32
9
Denmark
If you bought it online you will have EU distance selling laws to protect your purchase, also credit card protection. The forks are defective so get a refund and start again. The longer you leave it the potentially messier everything gets.
Yeah, i know. Altough, the fork was on the bike i bought online, so i have contacted both fox, and the dealership.
 

Christurbo

Well-known member
Jul 11, 2023
380
715
North Wales
If this was me , the bike ridden 20kms ? Straight back to the shop!
If it is something internal in the fork , that's clearly poor QA and should not be the buyers problem.
Agreed to a certain extent but that could be days/weeks off the trail and the advice I gave would take 30 mins.

I always drop the lowers and slightly more as Fox use too much grease which impacts on harshness.
 

Christurbo

Well-known member
Jul 11, 2023
380
715
North Wales
I only get play, when I turn the fork 90 degrees. I disassembled the headset and greased it up, I also tried without the brake caliper. It is definitely the fork..
That sounds to me like it could also be the hub brought into the equation that needs to be ruled out.

Put it in a stand. Remove the wheel and get someone to hold the frame whilst you check for play at 90 degrees and check it’s still there with no wheel.
 

Spin

Active member
Dec 24, 2021
181
228
Australia
Agreed to a certain extent but that could be days/weeks off the trail and the advice I gave would take 30 mins.

I always drop the lowers and slightly more as Fox use too much grease which impacts on harshness.
Yeah but one thing worse than buying a new bike and not getting to ride it until a warranty issue is corrected is voiding warranty by touching the problem yourself.
 

Simonp3

Member
Aug 21, 2020
32
9
Denmark
So i got a hold of my mates Mondraker Dusk R, also brand new. He's got a Fox 36 Fit4 installed. It does the same thing!
 

Heated

New Member
May 18, 2024
15
4
new zealand
Reviving this, Did you ever solve it? I've had knocking 36's in the past and fox just say 'nothing wrong' which is bullsh1t!!
The reason i found this is my new 38 on my Reign E+ is knocking and on the reign it radiates through the frame which makes it very loud(yes its the fork as put in anther bike)
 

Simonp3

Member
Aug 21, 2020
32
9
Denmark
Reviving this, Did you ever solve it? I've had knocking 36's in the past and fox just say 'nothing wrong' which is bullsh1t!!
The reason i found this is my new 38 on my Reign E+ is knocking and on the reign it radiates through the frame which makes it very loud(yes its the fork as put in anther bike)
Hello

Yes, it is solved.
It was solved ln mine, and my mates Mondraker with fox 36.

The fork bushings needs to be replaced, and after that, all is good.
 

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