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Pikes - Leaking damping oil

24 posts & 9 voices | Started 2 years ago by PeterPoddy | Latest reply from deertrackdoctor

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PeterPoddy - Member

It happened to mine at the weekend, the damping oil leaked into the lower leg leaving me with 60mm of travel

No problem, I know how to fix it, so they are in bits now, and I had a look through some old threads, but there's not really the answers I'm looking for

A)
Anybody managed to find the correct size O rings without stumping up £18 for a service kit? simplybearings have a fair few sizes that are close, but I'm struggling to find the small one that seals the shaft. It's about 3.5mm in section, and the O/D of the shaft is 12.5mm (Micrometer) so I'm guessing about 12.2-12.3mm I/D for the O ring?

B)
I've heard the shaft can be made undersized? Any ideas what is SHOULD be, so I can check?

Cheers

EDIT
I can't see any damage to the O rings or shaft, but the oil still leaked. Should there be something visible?

Posted 2 years ago #
PeterPoddy - Member

I think I might be answering my own question but, this one?

http://simplybearings.co.uk/shop/index.php?cPath=19_4501

Posted 2 years ago #
stumpy01 - Member

I had to take my Reba's apart last week after the same thing happened.

I serviced them a while ago & put it down to a poor job done. When i took it to bits the first time, everything looked nice & clean & undamaged so I used the original bits to re-build it, even though I bought the service kit from tft, just in case.
This time, I thought I would change all the seals in the damper leg to try & stop it happening again. First stop, I looked to change the inner & outer o-rings on the damper plunger (the white disc that slides onto the shaft). None of the o-rings in the kit were an exact match for the ones that came off it. I put the closest ones in, and tried it out, but the outer o-ring was too big & the inner o-ring too small, so in the end I just used the originals again.
Last weekend I did Penmachno Friday, Cader Idris Saturday & the MBR at CyB on Sunday & they seemed fine, so fingers crossed.

So, I guess what I'm getting at is don't rely on the service kit having the right seals....

Sorry, don't know what the correct shaft diameter should be - could have measured mine last week when they were in bits.
And, my o-rings & shaft all looked fine so am not sure why it didn't hold the oil the first time round - perhaps something got squished when being re-built??

Posted 2 years ago #
PeterPoddy - Member

Hmm. I've toyed with just putting them back together as well. These have never been apart until last night and have been fine for a fair bit of hard usage (Alps included), but I progressively lost travel all day on Sunday....

Simply Bearings have the one above that is pretty much a perfect match for the inner shaft seal, and about 3 that might fit the outer seal. I'm gonna order all 4 sizes and experiment I think.....

Might ring TFT about the shaft?

Posted 2 years ago #
stumpy01 - Member

Yeah - don't know why they all of a sudden seem to go. Mine lost lock-out initially, so I dumped the air out of the fork to check for full travel & that's when I realised that the damping oil had been dumped into the lowers, as I was only getting about 50-60mm travel.

I'd just try a variety of seals seeing as they are pretty cheap & you can swap them in & out to check for fit easily enough while it's all dry.
Just be aware that with the outer o-ring you need to make sure the OD isn't too large. The new o-ring that I attempted to use, was only slightly bigger, but there was no way I could re-fit the assembly in the upper leg, as it just tipped it from a tight fit to a serious interference fit & I didn't want to force it in and get it wedged.

Posted 2 years ago #
PeterPoddy - Member

I've just ordered some of the ones I linked to above, which are the only ones I can find near the correct size (It's pretty damned close, but you should try measureing an O ring!) and 3 other sizes close to the outer one. I shall report back with my findings.........

Posted 2 years ago #
juan - Member

Insert sarcastic Fox fork comment here

Posted 2 years ago #
Scienceofficer - Member

You mean about how poor their service interval is for 'british conditions'?

Posted 2 years ago #
PeterPoddy - Member

Rockshox problem fixed with £1.49 O ring.

Fox problem Fixed with £220 new stanchions.

Posted 2 years ago #
Scienceofficer - Member

heh!

Posted 2 years ago #
Stoner - Member

Slightly OT, but may be of benefit for those of you reading this thread...

A while ago an 07 set of Rebas with the red plastic motion control damping circuit wouldnt lockout properly. When you turn the blue knob around to lockout it wouldnt go "home" with a solid feel, it was more of a squidgy tightening, finishing off short of the lockout position.

I removed the damping circuit and everything seemed to be fine. I spoke to Flooks to ask his advice/supply a replacement, he said that there were no replacement units in stock, but when I mentioned I was trying to open up the gate to strip the whole unit but couldnt he said that you could unwind the red "grid" from the top cap as it has a LEFT HANDED Thread. Once open, I could see where a rubber seal (convoluted shape) had got bound up in the damper control knob stopping it close properly. A little shimmy and reforming it and it was back in position nicely.

SO if you get similar symptoms, assuming you havent shagged the rubber seal (I bet you cant get it as a single part from Fisher ), you can follow these instructions to fix it.

Happy servicing

Posted 2 years ago #
Bumhands - Member

Out of interest is there anything worth considering other than Pikes now?

A few years ago - there was no other real option for All Mtn riding.

- Lock out
-130mm travel
- bolt thru

Posted 2 years ago #
PeterPoddy - Member

Stoner, that's valuable info there mate, so thanks for that. I'd wondered how they came apart before myself.

Posted 2 years ago #
Stoner - Member

flooks was enjoying teasing me along until I worked out it was LHThread all on my own

He sure knows his onions though.

Posted 2 years ago #
glenh - Member

Stoner the seal under the top cap is a common source of problems (and leaks out of the top cap).

As you say though, it's easy to fix once you realise that it comes apart if you turn it in the correct direction!

I think it tends to get muffed if the fork is compressed while upside down (or on it's side), or the fork is over filled, as the oil is in contact with the seal rather than the air.
The oil gets pressurised as the damper compresses and if any forces it's way past, it can deform/fold the seal as forces a bigger gap than air.

Posted 2 years ago #
Stoner - Member

cheers glen. That makes sense now.

Posted 2 years ago #
PeterPoddy - Member

Update - O rings arrived today, and the fork is back together. The inner shaft seal is a slightly different size and seems to fit a bit tighter. Which could be better! We shall see. But it could be a while before I ride the bike again.......

Posted 2 years ago #
Stoner - Member

cheers PP
When you know for certain, can you post up a spec for the rings your bought that worked.
ta

Posted 2 years ago #
PeterPoddy - Member

Stoner - yes no probs mate. I think the important inner seal is the one I linked to above. It was the only one they had that was close. I ordered 3 slightly different ones for the outer seal, but after trying them out and getting the micrometer on them when stretched over the "base plug" they seem to be virtually indistinguishable once fitted. The plug certainly fitted into the base of the upper leg nice and snugly, put it that way!

Posted 2 years ago #
deertrackdoctor - Member

nice work gent s
my lockout initialy failed and looks like i have the same problem!
i was going to head to local John deere dealer ( amazing range of spares in there stores)
but if you would be as kind to post a link for the correct seals you will save me a lot of hassle and £££££ thanks peter
p.s i dont suppose anyone has an exploded diagram with sizes/tolerances and o ring sizes ? Is that something a sram dealer can access ?
thanks again chaps DTD formerly SarahBauz (before the ban)(;-0)

Posted 2 years ago #
bungalistic - Member

Cheers for the info above about damping curcuit, mine are leaking all the time, so i'll try take the damping circuit apart as you have said (I presume it is the same for coil 426's) and sort out the what should hopefully just be dodgy o-rings.

On a similar vein, since I never use lockout is it possible to possibly switch out the lock out damper unit for the domain style damper unit. Seems to have less leakage issues, anyone tried this, will it even fit?

Posted 2 years ago #
stumpy01 - Member

I'd be amazed if you can get the exploded dgm you are after with o-ring sizes etc. listed.

As for replacing the lock-out bungalistic - I think you can if you change the red damper unit in the leg & get a new cap for the fork leg that you twizzle.
I think peterpoddy has done a guide somewhere....that means you don't have to buy a new damper unit, just undo the spring, that lies within the remote lock-out version.

Posted 2 years ago #
PeterPoddy - Member

Just checked my link above and it's not working, sorry

The inner seal (on the base plug at the bottom of the damping leg, that the shaft slides through) is VERY close to 3.53mm cross section by 12.29mm internal diameter. That's a tiny bit bigger than the original, with a slightly fatter x-section. Once fitted it feels a bit tighter than the one I removed.

For the outer seal I ordered 3 sizes to try them out -

2.62 x 22.23
2.50 x 23.50
2.50 x 23.00

I can't remember which one is in there offhand, but they all seemed pretty much identical once fitted. I'll get back to you on the exact one, but IMO it makes little or no difference.

It'll be a couple of weeks before I get to try the forks out, but they're not leaking standing in the garage!

Posted 2 years ago #
deertrackdoctor - Member

nothing to loose here mate thanks Peter
i will strip it clean and go to John deere dealer and try to get a match.
i will let you know how i get on
thanks again DTD

Posted 2 years ago #

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