Refill Rockshox Fork with Oil

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Refill Rockshox Fork with Oil

Postby redeuca » Tue Aug 20, 2013 1:06 pm

I have had a slow oil leak from the rebound adjuster on a set of Rockshox Dart 2 forks and it's time to top up the oil.

I am wondering if it is possible to do without disassembly. From what I've read in the manuals and online, it seems the lower legs need to be removed or at least partially so. Is it possible to add the oil without the need for removal? Can it just be topped up directly by injecting through the bolt hole?

I just want to save time & effort if possible.
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by BNA » Tue Aug 20, 2013 1:16 pm

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Re: Refill Rockshox Fork with Oil

Postby Marx » Tue Aug 20, 2013 1:16 pm

Yes, you can simply inject additional oil through the bolt hole – for the lower oil bath.

But:
Oil volumes do effect fork dampening & movement. Too much or too little & they’ll behave differently. Do you know how much you have lost in the lower oil bath, and how much is still left in there?
(oil volumes are usually measured before it goes in, as apart from gauging the level when it's already in there).



I’ve serviced Rock Shox SID forks (2008 model) & found grit/dirt in in the oil bath & internals.
I reckon it’ll be worth replacing the oil/cleaning components & maybe replacing your seals, to be sure your forks are set up to specifications. Then you can be confident that they’re working as they are supposed to work.
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Re: Refill Rockshox Fork with Oil

Postby ProCelebrityGolf » Tue Aug 20, 2013 10:00 pm

The short answer is technically, yes - it is possible to undo the bolt a few turns, tap it into the fork, then unscrew it completely and inject oil straight into the lower fork leg.

However...

if indeed you have a slow oil leak then you might benefit from changing the crushwasher on the bolt in the lower leg so it doesn't keep leaking afterwards.

the previous poster mentioned about oil level affecting how the fork performs and this is a very valid point - you can't really know how much oil has leaked out so you'll presumably be adding a few ml at a time and having to repeat the process to fine tune the performance... to the point where it's probably just doing this job right the first time and removing the lower legs completely.

taking the legs off solo air rock shox forks is not overly difficult, rock shox youtube videos are very helpful in this regard. a full service can be done reasonably quickly and easily - apart from the oil itself, the only 'special' tool you need to buy/borrow is a pair of internal circlip pliers and a suspension fork pump.

Good luck!
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Re: Refill Rockshox Fork with Oil

Postby ProCelebrityGolf » Fri Aug 23, 2013 12:52 am

in addition to the official sram rock shox videos on youtube this link might prove useful (pics and text only)

http://www.bikeradar.com/gear/article/w ... ice-24649/
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Re: Refill Rockshox Fork with Oil

Postby bychosis » Fri Aug 23, 2013 6:52 am

I've done my forks twice recently. They had a leak of oil and after the first service I just cleaned and replaced the oil (with the correct weight oil) the leak reoccurred, meaning the forks were no better than before the service within a few minutes riding. I now have an o-ring kit waiting to be installed that should solve the problem. Apparently it is not uncommon in the motion control damper in rock shox forks. My symptoms were fork bottoming out at about half travel.

The sRAM videos are great, four of them to complete my reba rebuild. One video for each task depending on your model there may be some different ones.
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Re: Refill Rockshox Fork with Oil

Postby redeuca » Sat Aug 24, 2013 1:48 pm

Thanks for the replies and links. The manuals and videos are helpful.

I removed the forks, which incidentally was difficult, and cleaned the shafts,and inner legs. I replaced the crushwasher, although am a little suspicious of the o-ring for the rebound adjuster so may need to change that as well, refilled with oil and reassembled.

(edited)
On reassembly, the rebound adjuster knob rod doesn't seem to be able to be reinserted into damper rod as the part that accepts the adjuster knob seems to have disappeared into the rod. How can this be repositioned?

I tried to correct this by removing lower legs and pushing the damper rod down. When I did that the part reappeared near the end of the damper rod. Then I attached the screw and rebound adjuster and extended the rod, which seemed alright, until I reassembled the fork and have been unable to reengage the rebound adjuster correctly with the damper.

Suggestions to correct this problem?
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Re: Refill Rockshox Fork with Oil

Postby ProCelebrityGolf » Mon Aug 26, 2013 11:22 pm

Sorry I'm reading this but I'm very tired so it's taking a minute to make sense!

So initially you put new oil in the lowers and slipped them back onto the stanchionss but couldn't reconnect this bit

http://www.bicyclehero.com/au/rockshox- ... pQod6zIA7g

because the rod was pushed up inside the damper leg.

what was the next problem?
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Re: Refill Rockshox Fork with Oil

Postby redeuca » Tue Aug 27, 2013 11:07 am

ProCelebrityGolf wrote:Sorry I'm reading this but I'm very tired so it's taking a minute to make sense!

So initially you put new oil in the lowers and slipped them back onto the stanchionss but couldn't reconnect this bit

http://www.bicyclehero.com/au/rockshox- ... pQod6zIA7g

because the rod was pushed up inside the damper leg.

what was the next problem?


I was a bit frustrated when I wrote that and I'm not sure of all of the parts names.

http://images.esellerpro.com/2375/I/567/467/R5037000.jpg.
This shows the rebound adjuster and the damper tube.

Your assumption correct. There is a part that sits inside the bottom of the damper rod that the adjuster's pin connects to. It's this part that has disappeared into the damper tube, thereby preventing the insertion of adjuster's pin. The fork's rebound speed can't be controlled.

I can see the part, and I've been able to manipulate it closer to the end of the damper rod with an allen key, but it' doesn't sit firmly in place.
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Re: Refill Rockshox Fork with Oil

Postby ProCelebrityGolf » Thu Aug 29, 2013 9:57 pm

OK - I think I understand what you're describing - but I've never encountered this problem myself.

I've serviced my rock shox recon forks several times but they're 29er size so the ends are presumably different to your forks and I've never had to remove the bottom ends of the internal rods.
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Re: Refill Rockshox Fork with Oil

Postby redeuca » Sat Sep 07, 2013 6:20 pm

ProCelebrityGolf - Thankyou for your assistance.
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Re: Refill Rockshox Fork with Oil

Postby ProCelebrityGolf » Mon Sep 09, 2013 10:32 pm

I took mine apart over the weekend to see if I could replicate your issue. I noted (on mine) that the bolt that inserts into the bottom of the lower fork leg and which threads into the bottom of the damper rods has the hex shaped hole which my adjustor knob pushes into and twists for adjustment.

So on my 29er forks there is this bolt (which is one piece) and then this connects to the threaded ends of the damper rods. When I reassemble the fork I have the stanchions held horizontal with the steerer tube clamped in the stand. I pull both rods out so they are extended out as far as possible and then gently slide the lower legs on (being careful not to fold the rubber lip of the dust seals on the lowers). Once these are on and slid on completely then I can see through the holes in the end of the fork and I can see the threaded ends of those rods where my bolt connects.

Does any of this sound familiar to what you did?

Did you do any sort of work on the lower end of the damper rods during your service? (on my fork you do not need to touch that end at all really)
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