[Udi]

dhkid -
Thanks, will probably pull mine apart on thursday.

Rick -
Remove the rubber membrane, it's a seal (no through hole). Start and end the process under a bath if possible to ensure air can't enter like you said. I just used a cup of oil to bath the main port's end in, no need to bath the whole thing unless you have one handy really.

If you do have a full bath, you can do the bleed I mentioned above, and then close the secondary bleed port + open the piggyback end + IFP bleed screw, and blast more oil through to ensure air is out of the piggyback section also.

After that, set the IFP depth (with the piggy full of oil to keep the IFP submerged) and close everything up + clean + test.

Stock IFP depth varies depending on stroke length, off the top of my head it's 35mm for 3", and 28mm for 2.75".. guess you can make an educated guess for other stroke lengths from that.

 

[Rick205]

Excuse my ignorance, but how do i 'set' the IFP depth....? - would i have to reset it if i didnt bleed through the piggyback or is it something i have to do regardless?

- Ill have to look at a schematic as this is beginning to sound more complicated than before..

-EDIT- I have done some homework and understand how to set the IFP now.

Ill post up my results when i have done the bleed tomorrow - need the bike ready for the weekend...

 

[Udi]

IFP = internal floating piston.
It lives inside the piggyback reservoir, and seperates the damping oil and air. The fox one is probably the easiest to work with, it has a 2mm keyed bleed screw on the side facing you.

Setting its depth involves measuring from the top of the screw to the top of the open reservoir. What is your shock's stroke length?

It's worth setting/checking regardless IMO, especially now that you've drained pressures, removed oil, etc.

 

[Rick205]

I knew it would be internal floating piston - but had no idea what it looked like - i found a picture on here with a great step by step bleed of a dhx coil - shows how to set the ifp too which i assume is the same.

Its a 3" stroke so 35mm from the top to the piston itself, ill measure it with verniers i suppose to make sure its correct - 28mm from the top of the screw if thats right.

Thanks for all the help UDI, as i say, ill let you know how i get on.

Rick

 

[Udi]

No worries.
Quick tip - if 35mm is the correct depth, set it to 33mm with your ruler or whatever because it actually moves down a bit once pressurized. If you need to pull it out, use a long screw with the same thread in the hole and use pliers on that to pull it up with. Remember to keep the IFP submerged (don't need to submerge the whole shock, just fill the chamber) while you set the depth so air can't get in.

 

[Rick205]

I got on with this today, i did the bleed once, but no good, put it back on the bike and its noisy and still inconsistant rebound.

Took it off again, re-bled and again no good- noisy on the bike and will rebound correctly (slowly) deep into its stroke but if i compress the bike only say 2 inches into its stroke it just springs straight back up with no rebound control at all - it would ride like crap rebounding slowly on hits then when bucking me up over jumps etc.

There is NO air in the system, i cycled oil through the shock (all in a bath) several times and no air bubbles - i then bled the ifp several times with no air bubbles before setting and refitting.

Its still arsed though , now im annoyed and covered with oil too!

Ah well, im going to either buy another shock now or send it for service (£100 though :-( )

Rick

 

[Udi]

If it's noisy then there's air in it pretty much, a small amount of noise is acceptable but if it's inconsistent noise then it's a dead giveaway of air in the damper. In my experience it's pretty hard to get an air free bleed in one go, I did as good a job as I could, rode it for a while, and then spent some time pumping the shock with minimum pressure in the air chamber (30-40psi I guess, whatever you feel like) and the reservoir open.

Basically, reservoir cap removed, chamber topped up with oil to stop air entering, and then removing the IFP bleed screw. Once you've done that, you can manually pump the air shaft in and out slowly to encourage any leftover air bubbles to enter your mini oil bath inside the reservoir. Tapping the propedal knob and black reservoir arm with the plastic end of a screwdriver will help encourage any trapped bubbles upwards.

Apart from that, my only suggestions would be reconfiguring the rebound shimstack and/or trying different oil weights but that's a lot of messing around.

If you're still not happy, it sounds to me like the shock mightn't be the best choice for the bike... the overall ratio isn't tooo bad but I have no idea what the leverage curve is like.

By the way, I found out why my rebound damping was playing up... damper piston's glidering = bye bye. Never seen this before.

 

[dhkid]

****!! thats something you dont see everyday.

 

[Udi]

I'm actually a little lost on what to do.

I can't get the part through fox short of them rebuilding it under warranty or not (either way time/hassle involved), and they'll possibly whine that I had it open myself.

I'd love to source an aftermarket glide ring but wouldn't know where to go to find one... do you?

I've got a spare DHX Coil glide ring, but it's a larger diameter... my idea was to split the glide ring diagonally (to size) and just run it as a split glide ring. The boxxer's rebound piston has the same setup. But I wonder if there's a certain thickness of ring (and seat depth) required to run a split guide ring to prevent it from breaking up under pressure... because in that case, the DHX ring is fairly thin and the seat relatively shallow...

 

[toodles]

Udi - maybe give the guys at Push a holler? They do aftermarket glide rings and might be able to send you the bit you want.