[Closed] Foix FIT damper service - As hard as it looks?

Oh, numpty question:
Is the FIT cartridge the AIR or the DAMPING side? I've just realised I don't know! (I think it's damping)

The FIT cartridge is the compression dampening and rebound side of things. The air spring is in the other fork leg.

But that's about as far as I can help you, as both my forks are open bath, partly because I'm too cheap to buy a FIT cartridge fork, and partly because I've heard the FIT cartridges are beyond most amateur bike fettlers capacity to service.

I do Ok servicing my open bath forks, but I'll let someone with more expertise tell you how difficult it is to do a FIT cartridge...

and partly because I've heard the FIT cartridges are beyond most amateur bike fettlers capacity to service.

Mmmmmmmmm not sure. I've read the instructions. It's a long winded faff, for sure, but it's only unscrewing things and putting them back together at the end of the day. 🙂

To be honest, I'm probably not going to do it. If the forks were mine, I'd be in there already, but they aren't....
He did call TFTuned and they rubbed their chins when they heard what the shop had said!

But I am toying with the idea!!

Not being in possession of all the facts or having the fork in front of me I can't say for sure (although when has that stopped anyone commenting 😉 )
The seals are replacable on the FIT cart, and we offer services on just the FIT dampers.
The issue is if parts have been damaged inside the cart. and I'm not sure whether you'd be able to get the parts Peter.

Why would you throw a way a damping cartridge and put a brand new one in, when all you need to do is replace the seals in the old one?
Christ even sending the whole fork away (not just the damper assembly) would cost more than £100 or so to give it a good seeing to.
I think you need shaft clamps to get into the RL damper, but not sure about sourcing new seals? Simon @ Loco Tuning will be able to advice / do the work im sure.

Oh and the LBS are talking out of their arses, without taking it apart how could they possibly know?

If it's an F-Series 32RL then it has open bath damping- not FIT damping. You certainly could replace with a FIT damper but tbh you'd be better off buying a new fork in the sales or sending it to someone who knows what they're doing like MOJO or Loco. (If you don't fancy servicing yourself I mean)

In terms of home servicing its very easy until you start stripping the actual damper down, which is much more involved. This is what your shop is saying they don't want to do, they're going to order a new damper assembly and fit it (Changing the bath oil at the same time). Mojo/Loco can strip the damper and service as required.

Not being in possession of all the facts or having the fork in front of me I can't say for sure (although when has that stopped anyone commenting )
The seals are replacable on the FIT cart, and we offer services on just the FIT dampers.
The issue is if parts have been damaged inside the cart. and I'm not sure whether you'd be able to get the parts Peter.

Yes. This is the thing..... Can YOU get the parts? I said he's better off sending the fork away to you whilst I do the ret of the bike.
This is why I like Rockshox..... 😉

Why would you throw a way a damping cartridge and put a brand new one in, when all you need to do is replace the seals in the old one?

Because you are a BIKE SHOP and that is faster and makes more profit. Which is what I'd expect, nothing wrong or new there!

If it's an F-Series 32RL then it has open bath damping- not FIT damping.

Rebound (red knob 😉 ) is on the bottom of the leg in FIT carts.

We offer just a FIT damper service, so customers can service the chassis, wiper seals etc and send the damper into us.

Rebound is on the top, with lockout in the middle.....

double post

Not sure it's any help, but the Fox F125RL forks from my 2012 Giant Trance X2 are definitely open bath. I considered upgrading to FIT, but the quote from Mojo was around £200 (on top of the £100 for the service).

EDIT: Turns out I was right, it wasn't any use 🙂 as LoCo chipped in with a much more useful answer as I was typing.

OB cart then, so they're saying the damper is screwed and to replace with a FIT damper (which seems a touch pricey to me).
Refer back to my comment about not being in full possession of facts/fork infront of me etc 😉

SO what we're saying here is that the (Large, posh) bike shop is talking out of their arse?

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If it's an F-Series 32RL then it has open bath damping

Like has been mentioned above- how can they possibly know whats wrong with it without taking it apart. Although a harsh top out does seem quite likely to be the oil draining out of the damper - but I would want to see it before making the call.

Iv rebuilt a FIT damper from a 36 fork without any of the special tools I was told I needed. It was quite easy - didnt change any seals though- mine just had air trapped under the diaphram.

Thats an OB damper as loco says.

Ones in good working order sell for ~£200-250 s/h tops.

No Peter, it's an OB damper and I think they are suggesting an upgrade to the FIT damper system,.

ndthornton, there are two types of FIT damper the 'older' one fitted to the 36 is easier to do, best to replace the bladder if it's 'burped' as they tend to distort and do it again fairly quickly 😀

Lovely! 🙂

As easy to service as RS then?
Are there any technical manuals about like SRAM do?
What weight damping oil do I need?

This shows the oil volume and type:
http://service.foxracingshox.com/consumers/Content/Service/oil_volumes.htm

Tech info here:
http://service.foxracingshox.com/consumers/index.htm

I'd do a simple oil bath change and clean the wiper seals, lube the foam rings and put it back together. DO NOT forget to check the air chamber as it's likely most of the lower leg lube oil has migrated up there. There is info how to do this in the above link, but you might have to dig around for it.

Chances are that will sort the fork out unless its been run without oil for a long time. If it doesn't work you've got the choice of rebuilding the damper youself or sending it off to loco/mojo.

just out of interest does this void any warranties?

They'd have no way of knowing you'd had it apart if done properly. I believe Fox encourage users to do wiper seal services themselves anyway, but obviously I don't speak for the company so couldn't say 100%

Cheers Roadwarrior, good info. I'm going to give it a shot in the next day or so 🙂

As we've established they're actually the open bath model, then yes its a pretty simple procedure. Just get yourself a 32mm dust wiper seal kit, a bottle of Fox 10wt green oil, and have the following tools handy:- 22mm socket, 10mm socket, seal pick, plastic faced hammer.

Then, follow the instructions [url= http://service.foxracingshox.com/consumers/Content/Service/Forks/FLOAT/FLOAT_RL.htm ]here[/url]

22mm socket? 26mm isn't it? 🙂

26mm, 6 sided and machined ideally, if the damper is knackered though they are rebuildable with kits, various things can cause klunks and clips in those.

Got 24mm (Rockshox) and 27mm (GPZ500 rear spindle IIRC!)

arse.

22mm socket? 26mm isn't it?

Yep - 26mm, sorry!

Other things to have on hand; fox float fluid for the air chamber (3 or 5cc required), crush washers for the base and syringes to measure out the float and damper fluid. (Last time I got 10 from ebay for about £3).

You might not need the washers, but if the fork leaks when you put it back together it's annoying having to wait for a delivery before you can ride!

I'm currently halfway through a service of my Fox forks, while I await some bits. I was looking for online guidance yesterday and found this, which is basically the answer to your question:
http://www.hackracer.com/2012/04/tech-part-3-of-4-how-to-replace-seals.html
http://www.hackracer.com/2012/04/tech-part-4-of-4-how-to-bleed-fox-fit.html

Incredibly detailed, illustrated and comprehensive. Useful! Part 4 above is particularly relevant to your query.

roadwarrior, can you elaborate on your point about checking the air chamber? Mine (Float 100s) are currently disassembled until I get home tonight. All the oil has definitely drained out of the damper side. The air side oil has drained out of the bottom but there is still visible oil under the top cap on that side. I was unsure as to whether it was essential to drain and replace this as well as I thought it might be sealed enough that it was ok. I haven't found a definitive answer online so if you can advise I'd be most grateful!

flatboy; see here; http://service.foxracingshox.com/consumers/Content/Service/QuickTech/AllAirSpringQuickService.htm

Ignore everything before step7. You simply remove the air side top cap (DONT FORGET TO RELEASE THE AIR VIA THE VALVE FIRST!) empty out the old fluid and clean out everything and replace with 5cc of float fluid. The oil volumes chart I linked above confirms the quantity.

The oil in the air chamber will effect the linearity of the fork, you need some for lubrication but too much will cause the fork to ramp up sharply due to the reduced volume of air in the chamber.

You'll likely empty out more than 5cc because it tends to migrate from the lower leg.

One other thing- that link above is helpful but I would not wash any of the fork internals out with soap and water. If you want to clean anything use IPA or some solvent that will evaporate completely. Last thing you want is water and soap in your damper fluid.

nice one, cheers sir.

doing this job has made me think more than ever before that i need a torque wrench. not having one, i assume i'm going to die after i tighten everything up again... 😯

removed. I've already said that.

The oil migration issue, was mainly with the newer spring assemblies, that had the foam ring fitted below the air seal on the piston, these are replaced with scraper/lip seals.

Another quick question, while the experts are clearly in the house - I noticed that at the very bottom of both lower legs there are what seem to be black rubber washers (one per side). At least one is loose and I was a little worried it had come detached from somewhere, but seems to sit in what looks like the correct spot at the bottom of the leg with a bit of wiggling. I take it this is all ok?

That's the crush washer. They're consumable. Keep using them until they weep oil, then replace. Mojo sell them, as do others I assume

Torque wrench? Nah, just nip everything up and don't go crazy and strip any threads.

Not the crush washers - on the inside, similar to the foam rings in appearance (but black), and smaller so they sit right at the bottom of the lower legs. I can put a pic later. I'm fairly sure they're ok where they are (as I can't work out where else they could have come from! but am not sure.

Bump stops, clean, little grease and locate in lowers so holds them in place 😉

Good stuff, I really appreciate the input chaps - I won't forget you Loco when I **** it all up later on. 🙂

Remember tighten everything up till it shears and then back it off a 1/4 turn, that's just right 😯 😉

The oil migration issue, was mainly with the newer spring assemblies, that had the foam ring fitted below the air seal on the piston, these are replaced with scraper/lip seals.

Loco makes a good point here, and its worth reiterating in case anyone missed it.

There was a batch of Fox forks from 2010-2012 which had a design fault. They added a foam ring to the air spring piston to keep the seal lubed and running smoothly. Here's a pic of the air spring showing the foam ring (yellow) and rubber seal (black)...

[img] [/img]

However, over time it had an undesireable side-effect of promoting the transfer of oil from the lower fork leg to above the air spring. This had two results - 1. Eventually leaving your lowers in that leg dry, with no lube for the bushings, and 2. Oil being uncompressable, the performance of the air spring was degraded and travel reduced. However, it happened so gradually that it was hard to notice until one day you suddenly realise you are only getting an inch of travel out of a 4 or 5 inch fork.

Fox never really admitted to the problem (I'm guessing American company + lawyers = liability issue), but did quietly tell their service agents to replace the foam ring with a rubber scraper seal anytime one of these forks came in for a service. They were also happy to send out the scraper seal FOC to any DIY maintenance owners who requested it. However, there's undoubtedly a large number of forks out there still with the problem if they've never been professionally serviced, or the owner never noticed the issue. For example, take a look at this thread [url= http://singletrackworld.com/forum/topic/fox-float-32s-lowers-oil-in-the-air-chamber ]here[/url]

So, if you're going to pull one of these forks apart yourself, take careful note of how much oil is above and below the air spring (should only be 5cc of blue float fluid above, and the Fox oil volumes table will tell you how much oil should be in the lowers). Then have a look at the air spring itself, and if its got one of those foam rings on it (not to be confused with the foam rings under the dust wiper seals!) then contact Mojo and get them to send you a rubber scraper seal to replace it with under warranty.

ok, more assistance needed! all done, cleaned, fox fluid added, oil added in what appears to be correct quantities from Fox, most of the assembly seems to have gone smoothly.

Problem - putting the controls back on the top assemble on the damper side, it appears that the rebound, lockout and compression controls have all seized together, i.e. once the controls are all back in place they don't do that they are supposed to. the fork compresses seemingly fine, but then takes literally 20 seconds to rebound. not ideal!

any ideas on trouble-shooting / remedial steps?