Fox Fit4 rebound needle replacement?

k3n!f

leaking out the other end
I have a 2016 Fox 32 with a Fit4 damper and the rebound needle has snapped at the rebound knob attachment point. I had previously asked the LBS to replace it, but they couldn't find the part without replacing the entire Fit4 damper. As a COVID project I'm going to service the fork lowers which I've previously had a bike shop do. I have found the rebound needle online for $15.

I have seen the Fox online instructions for servicing the fork. What I can't figure out is if I can replace the rebound needle without having to mess with the damper itself?

Any help appreciated!

Fork Fit4 damper rebuild

Rebound needle
379975
 

SummitFever

Eats Squid
I haven't done this myself but I would expect that you'd have to disassemble the entire damper to get the rebound needle out.

I will be doing a fit4 damper complete rebuild in the next week so should be able to advise further then (if you haven't already got it sorted).
 

k3n!f

leaking out the other end
That would be immensely helpful!

The online guide uses a Fox 34 whereas mine is a 32 with a different part number for the rebound adjustment needle. Looking at this diagram I can't tell if the rebound adjustment needle can be removed without messing with the damper shaft. It almost looks like it just slots in? (Although that would be too good to be true....)

379977
 

dazz

Downhill Dazz
Follow step 25 and 26 in that guide carefully. It's gonna be pretty damn tight and the heat will definitely be needed to soften the loctite. But yes, according to those drawings and guide, the rebound needle will then lift out of the damper shaft. What will you be using to hold onto the damper shaft to undo the base stud?
 

The Duckmeister

Has a juicy midrange
FIT dampers are a cartridge system, so while it is possible to swap needles, it's not a simple process, requiring a very intense rebuild. I don't know if the individual bits are openly available as spares locally.
 

ozzybmx

taking a shit with my boobs out
Are you sure you have snapped the rebound needle ?

I busted the exact same 2016 Fox Factory 32 FIT4 rebound assembly off at the attachment point on the bottom of the fork.

Ham fisted attempt at 6nm and popped it off with a socket. In hindsight, a confession on the fuckwits was probably in order.

The replacement assembly sent to me overnight express by NSD looked like the picture below.

The bottom part of what looks like the needle is actually part of the assembly, this screws into the shaft and meets up with the rebound needle.

You may only need this rebound assembly knob kit.

379986
 

ozzybmx

taking a shit with my boobs out
Keep the damper in the fork, it doesn't need to come off.

To get this assembly off, you will need to make up something to grip the shaft of the damper.

I got a set of Vernier's, measured the shaft, deducted 0.5mm and drilled a hole between 2 pieces of wood.
This did the same job as the proper shaft clamp pictured below.

Tighten the shaft, try to unscrew the assembly with the spanner, if it spins, tighten a bit more.
Only tighten enough till it unscrews, dont crush the damper shaft.

I have linked the Step Cast assembly from Cyclinic below but its for 2019+, I would be calling NSD and Cyclinic to see if they have a secondhand one laying around as I cant find the 2016 32 CTD rebound knob assembly online.

379987



 

SummitFever

Eats Squid
From the 2016 FIT4 for 32mm diagram it looks like the rebound needle is one piece and retained by the base stud. Once you've got the base stud off the shaft it should come away with the base stud.
 

Live2DieTrying

Likes Bikes and Dirt
To undo the stud, clean the damper shaft well with isopropyl alcohol, find an old inner tube and clean that too.
Wrap the tube around the shaft (clockwise looking down at stud) as tightly as you can.
Lots of wraps, then clamp it tightly in a bike workstand clamp.
Wrench on the stud until the locktite lets go!
 
Last edited:

k3n!f

leaking out the other end
So I ended up buying the rebound needle online to have a go at repairing this myself. Sadly my house doesn't have any tools, so I waited until I was staying with my parents over Christmas to use my Dad's epic workshop/machine shop if I broke something. I've never even tried a lower service on a fork, so I was jumping in the deep end and was very surprised about how simple the process ended up being.

When the rebound needle broke the shop told me it would be $350 for a new damper + installation fee. They also told me it wouldn't be worth servicing this fork, just ride it till it dies and get a new one. I followed their advice and have put about 10,000km on the fork since it's last service, so I expected to find a train wreck of wear on the inside....

I spent $40 getting the rebound needle delivered to my door and this took about 2 hours, including faffing reading the instructions on the Fox website.

These were the steps I followed:

Snapped rebound needle, it is also jammed so can't be adjusted
384428


Small amount of dirt in the fork, but pretty clean overall
384429


Amazed at the perfect condition of the stanchions, this fork is the smoothest I've ever owed, I think 6 years of use has burnished the bushings to perfection
384430


The culprit
384431


Home made damper shaft tool
384432


Burn it with fire to release the Locktite
384433


Shaft free!
384434


The culprit, there is a shit load of dirt which had corroded and seized the ball in position, I can see why they have updated the design as having an adjustable dial on the bottom of a fork is pretty stupid idea
384435


New ball bearing and spring cleaned, re-greased and ready for assembly
384436


Put it all back together and filled it up with some hydraulic oil, the fork was basically dry after 10,000km and this was the only thing I could find, a quick google suggested it will do a feasible job
384437


Clicky clicky click
384438


Back together
384439



10/10 will do my own fork servicing again.
 
Last edited:

safreek

*******
So I ended up buying the rebound needle online to have a go at repairing this myself. Sadly my house doesn't have any tools, so I waited until I was staying with my parents over Christmas to use my Dad's epic workshop/machine shop if I broke something. I've never even tried a lower service on a fork, so I was jumping in the deep end and was very surprised about how simple the process ended up being.

When the rebound needle broke the shop told me it would be $350 for a new damper + installation fee. They also told me it wouldn't be worth servicing this fork, just ride it till it dies and get a new one. I followed their advice and have put about 10,000km on the fork since it's last service, so I expected to find a train wreck of wear on the inside....

I spent $40 getting the rebound needle delivered to my door and this took about 2 hours, including faffing reading the instructions on the Fox website.

These were the steps I followed:

Snapped rebound needle, it is also jammed so can't be adjustedView attachment 384428

Small amount of dirt in the fork, but pretty clean overall
View attachment 384429

Amazed at the perfect condition of the stanchions, this fork is the smoothest I've ever owed, I think 6 years of use has burnished the bushings to perfection
View attachment 384430

The culprit
View attachment 384431

Home made damper shaft tool
View attachment 384432

Burn it with fire to release the Locktite
View attachment 384433

Shaft free!
View attachment 384434

The culprit, there is a shit load of dirt which had corroded and seized the ball in position, I can see why they have updated the design as having an adjustable dial on the bottom of a fork is pretty stupid idea
View attachment 384435

New ball bearing and spring cleaned, re-greased and ready for assembly
View attachment 384436

Put it all back together and filled it up with some hydraulic oil, the fork was basically dry after 10,000km and this was the only thing I could find, a quick google suggested it will do a feasible job
View attachment 384437

Clicky clicky click
View attachment 384438

Back together
View attachment 384439


10/10 will do my own fork servicing again.
I have used ATF twice now with no drama, presume this is as good ?
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
So I ended up buying the rebound needle online to have a go at repairing this myself. Sadly my house doesn't have any tools, so I waited until I was staying with my parents over Christmas to use my Dad's epic workshop/machine shop if I broke something. I've never even tried a lower service on a fork, so I was jumping in the deep end and was very surprised about how simple the process ended up being.

When the rebound needle broke the shop told me it would be $350 for a new damper + installation fee. They also told me it wouldn't be worth servicing this fork, just ride it till it dies and get a new one. I followed their advice and have put about 10,000km on the fork since it's last service, so I expected to find a train wreck of wear on the inside....

I spent $40 getting the rebound needle delivered to my door and this took about 2 hours, including faffing reading the instructions on the Fox website.

These were the steps I followed:

Snapped rebound needle, it is also jammed so can't be adjustedView attachment 384428

Small amount of dirt in the fork, but pretty clean overall
View attachment 384429

Amazed at the perfect condition of the stanchions, this fork is the smoothest I've ever owed, I think 6 years of use has burnished the bushings to perfection
View attachment 384430

The culprit
View attachment 384431

Home made damper shaft tool
View attachment 384432

Burn it with fire to release the Locktite
View attachment 384433

Shaft free!
View attachment 384434

The culprit, there is a shit load of dirt which had corroded and seized the ball in position, I can see why they have updated the design as having an adjustable dial on the bottom of a fork is pretty stupid idea
View attachment 384435

New ball bearing and spring cleaned, re-greased and ready for assembly
View attachment 384436

Put it all back together and filled it up with some hydraulic oil, the fork was basically dry after 10,000km and this was the only thing I could find, a quick google suggested it will do a feasible job
View attachment 384437

Clicky clicky click
View attachment 384438

Back together
View attachment 384439


10/10 will do my own fork servicing again.
Great stuff. Always seems scarier than it really is until you've done it.

I also neglected a Fox 34 Rhythm for a few years to the point it was starting to feel like the oil had gone sticky.

Opened it up suspecting a house of horrors, but it was immaculate inside, the oil was just starting to dry out. But still, modern oils are friggen amazing.
 

link1896

Mr Greenfield
Well done. That is shameful advice to not service and ride into the ground. One missing o ring placement in the design leads to a whole lot of dramas.
 
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