Fox 36 Bushes Knock...
 

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Fox 36 Bushes Knocking

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How much noise / play is “normal” for fox 36 forks?

Noticed mine today knocking on a ride. Thought it was headset but definitely forks. Brake on , rock and you can hear and feel the knock from air side leg.

I’ve never noticed it before which makes me think problem but my mates 36 is worse with about 200mls more than mine!

Mine have done 220 mls total but i had a service Grip 2 upgrade at about 120mls ago so only 100mls ish old.

Wondering if its normal or get em looked at before doing and damage. Or is it more if an annoyance than risking damage to the legs?


 
Posted : 13/05/2023 3:08 pm
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Shouldnt be knocking after that mileage, are you sure thats what it is.

Have you a floating rotor up front ?. They can click if you apply the brake and rock it forwards, and theres also a bit of stiction initially in the travel.

If in doubt, swop them out.


 
Posted : 13/05/2023 3:54 pm
weeksy reacted
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Mine was like that from new. Been back for warranty to fix it twice. Each time they rebuilt the damper and did nothing with the bushings… Gave up on that and paid for new bushings to be fitted - good for literally one ride, then knocking and harsh again. Tried alternative lowers - same. Good for one ride, then pish. X2 rear shock just blew again today for second time. Really quite disappointing.


 
Posted : 13/05/2023 4:01 pm
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Leave the bike upside down overnight and then go ride the next day. See how it feels.


 
Posted : 13/05/2023 5:11 pm
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Just had to warranty a 1 ride old pair of marzocchi z1 for the knocking noise ,occurs anywhere after half the travel.
It was the grip damper that was at fault.
All sorted in 5 days under warranty


 
Posted : 13/05/2023 7:38 pm
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If you stick your fingers between the arch and stanchion you can confirm its the bushings.

You can fit new bushings to the lowers and resize them as required.

Some GRIP dampers do seem to knock, and Silverfish seem to be a bit random at replacing under warranty, and denying there is an issue


 
Posted : 13/05/2023 9:31 pm
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So.. finger between the arch and play is negligible at the seal area.

Also I left the bike upside down and the knock has gone. Not ridden it to know if its cured. It started mid ride last week so not sure why and wherher it’ll just start up again.

Does leaving upside down just relube the bushings and the name i cant remember lubing system via the small grooves. Or does it diagnose the problem as being with the bushes if leaving upside down makes the noise go?


 
Posted : 16/05/2023 8:27 pm
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Fox bushings are supposed to be hydrodynamic, when you invert the fork the oil will run down into the bushings. If they are sitting the right way up most of the oil will run down into the bottom of the lowers (should still leave a film).

The 5wt PTFE is much thinner and less "clingy" compared to 20wt gold. GRIP forks that have been sitting upright for a long time can be quite dry at the top if you strip them.

Does your bike sit for long periods of time between rides?


 
Posted : 16/05/2023 9:04 pm
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Its normally used every week but before this ride for one reason or another yes, standing upright and unused for a fair while.

Suppose i need to store it upside down!


 
Posted : 16/05/2023 9:11 pm
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I have a new Fox 36 Rhythm fork with a knock seemingly from the bushings. It feels like a loose headset, axle, disc rotor or front brake caliper, except it isn't any of them as I have carefully checked them all.

I can feel movement between the stanchion and the back of the fork brace, just above the seal.

I understand that a small amount of play is necessary to allow oil circulation, but this is more than on any of our other current or past forks. One current set are Marz Z1s, which are essentially the same as a 36 Rhythm, and don't have the same issue.

I have spoken to Silverfish, who think it is unlikely, but have said if I send them in they will have a look. I can't see how the Grip damper could cause the fore-aft movement.


 
Posted : 16/05/2023 10:30 pm
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My 36’s have developed a knocking, got worse over the last couple of rides, definitely not headset or anything else I can find. Bushings seem fine, so I’m guessing it’s the damper issue?

Hopefully get them up to silverfish this week… what do we reckon, dodgy batch of forks so hopefully a rebuild and they’ll be reet, or generally a bag of 🤬 and better off sticking a lyric on?!


 
Posted : 29/05/2023 4:41 pm

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