Mountain Bike Reviews Forum banner
1 - 20 of 23 Posts

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #1 ·
This has been bugging me for awhile now so I thought I'd see if anyone else here has run into the same issue. My 100mm '07 Reba will occasionally eff up and give me about 1" of travel and stop dead. I can't do anything to get it through its full range of travel. The lockout knob is useless--does nothing to affect that 1" of travel. I get 1" and then a dead stop.

I end up pulling the right leg apart, find nothing obviously wrong, put it back it back together and the fork works fine. Full travel, lockout works correctly, etc.

For awhile. And then, one day, with no explanation, it will happen again. The only fix I've found is to pull the right leg apart and put it back together.

This has happened a couple times, but it started after I had the fork rebuilt a little over a year ago.

Anyone have any insight as to to why this would happen?
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #3 ·
Thank you for the info--but I don't think that's my problem. I'm reading that thread as saying that your fork sunk into its travel and you only got the top-most part of the travel out of it? Say, the LAST 50mm or so?

My fork is still at full extension--I only get the FIRST inch of travel or so and then it stops, hard.

I have tried letting all the air out of both chambers and reinflating, positive side first, and it had no effect. I had to tear apart the damper side and reassemble to get it to work. The second time it happened, I didn't even touch the air leg--just pulled apart the right leg, reassembled, and was good to go again.
 

·
ballbuster
Joined
·
12,718 Posts
No, I think this is right

Lugboot said:
Thank you for the info--but I don't think that's my problem. I'm reading that thread as saying that your fork sunk into its travel and you only got the top-most part of the travel out of it? Say, the LAST 50mm or so?

My fork is still at full extension--I only get the FIRST inch of travel or so and then it stops, hard.

I have tried letting all the air out of both chambers and reinflating, positive side first, and it had no effect. I had to tear apart the damper side and reassemble to get it to work. The second time it happened, I didn't even touch the air leg--just pulled apart the right leg, reassembled, and was good to go again.
I think this is exactly your problem. When it happened to me on my 26er Reba, it was topped out pretty hard. The o-ring between the positive and negative air didn't have enough lube around it, and it 'rolled' over, making it burp air between the positive and negative air chambers.

I say take it apart, do an oil change, check your o-rings on your air spring side, maybe just replace them for silly anyway (as long as you have it apart anyway) and slather it all up with fresh lube. If you don't wanna tackle this yourself, your LBS (make sure they are qualified to work on a RS fork) should be able to take care of this for under $50. IF your fork is an '07, it's due for service most likely.
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #5 ·
If it is my problem (i'm not saying it couldn't be, and I will give this fix a shot--I'm willing to try anything), then how is it explained that the second time I had this issue, I did nothing to air leg of the fork and was able to fix the issue?
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #6 ·
Okay, update. I checked the air pressures in the fork tonight, and then released all the air pressure out of the fork. I then pumped the fork up again. Same issue. I get the first 1" of travel and then it stops dead.

So, I pulled the damper out of the other fork leg and tried again. Same thing happened.

Then, I let all the air out of both chambers, and tried the fork action. My assumption is at this point, the fork should be dead squishy with no air and no damper installed.

I still have the same thing happening. :madman:

Can anyone shed some light on this?

Do I simply need to completely rebuild the fork again? It's almost worth me buying a new fork at this point, this thing has me so frustrated. I'm trying to get my SS running again and this fork isn't helping!
 

·
ballbuster
Joined
·
12,718 Posts
Read the previous posts again

Lugboot said:
Okay, update. I checked the air pressures in the fork tonight, and then released all the air pressure out of the fork. I then pumped the fork up again. Same issue. I get the first 1" of travel and then it stops dead.

So, I pulled the damper out of the other fork leg and tried again. Same thing happened.

Then, I let all the air out of both chambers, and tried the fork action. My assumption is at this point, the fork should be dead squishy with no air and no damper installed.

I still have the same thing happening. :madman:

Can anyone shed some light on this?

Do I simply need to completely rebuild the fork again? It's almost worth me buying a new fork at this point, this thing has me so frustrated. I'm trying to get my SS running again and this fork isn't helping!
Your problem is your air spring, not the damper. The damper doesn't do anything except slow down the movement of the fork, hence 'damping'.

*edit*

This was in response to removing the damping cartridge, and still not getting any travel. You basically took the damper completely out of the mix, so it can't be that.
 

·
Registered
Joined
·
682 Posts
I'm thinking that this issue could be caused by the level of oil on the damper side. If the oil level isn't correct there could be air in the damper side that is getting on the wrong side of the seal. When you pull out the piston and re-install it you may be resetting this problem.

Before you buy a new fork, consider sending this one to Push Industries. They have an excellent reputation with Fox rebuilds and recently started servicing RockShox as well.
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #9 ·
pimpbot said:
Your problem is your air spring, not the damper. The damper doesn't do anything except slow down the movement of the fork, hence 'damping'.
So, you're saying this will still happen with NO air pressure in the fork? I guess I assumed that if no air pressure was in the fork, then the full fork action should occur. That's what is confusing me.

Next step is to do what you suggested before (thank you), and tear the fork apart and replace seals again. Man.
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #10 ·
MichauxYeti said:
I'm thinking that this issue could be caused by the level of oil on the damper side. If the oil level isn't correct there could be air in the damper side that is getting on the wrong side of the seal. When you pull out the piston and re-install it you may be resetting this problem.

Before you buy a new fork, consider sending this one to Push Industries. They have an excellent reputation with Fox rebuilds and recently started servicing RockShox as well.
Honestly, I don't want to spend that kind of money on this Reba. I don't like the fork enough to do that. If I can't fix it myself, I'll find another option!
 

·
Registered
Joined
·
906 Posts
If the air spring has NO pressure, there's no way it's what's causing this IMO.

Have you ever checked/changed the oil level? My guess is vastly incorrect oil level, or a blocked valve on the dampening side. If you mess with the dampening knob does the condition change?
 

·
Registered
Joined
·
358 Posts
I spoke with SRAM about this. All the oil on the damper side has migrated below the a piston washer. If you open the top of thye damper side you will probablly notice that there is not much oil up top. You must remove the lowers and replace the washer and seal at the bottom of the leg. Sram sent one to me. It was a easy fix and the fork has returned to perfect use.
 

·
Registered
Joined
·
24,083 Posts
He's right, it is to do with the right leg and oil leaking into the lowers between the MC rebound assembly and not returning above it. I had to fix this on a friends bike, but I dind't have the time to fuff about and just swapped out his old rebound damper unit for my old 26" one and the fork has worked fine ever since. I just ordered up a new rebound assembly and piston for his fork, will install it sometime soon.

I have attahced a JPEG with the exploded view, hope maybe this helps.

Onetrack said:
I spoke with SRAM about this. All the oil on the damper side has migrated below the a piston washer. If you open the top of thye damper side you will probablly notice that there is not much oil up top. You must remove the lowers and replace the washer and seal at the bottom of the leg. Sram sent one to me. It was a easy fix and the fork has returned to perfect use.
 

Attachments

·
...
Joined
·
1,316 Posts
I tend to agree with Lynx, I had a similar problem in the left leg. (Seal between the chambers was not set correctly and the oil from the Pos chamber leaked down to the Neg chamber) Even though it is a small amount of oil it caused a great deal of problems. I had less than half travel with all kinds of clunking/scraping noises.

FWIW
Putting the 150 bucks to PUSH the reba would be worth it IMHO. It will be like a new (and better) fork afterwards.
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #15 ·
The 4 posts above make sense to me. I did notice that the oil level seemed really low in the damper leg when I pulled the compression assembly out of the top. The oil level should be at the bottom of the compression assembly and it looked to be much lower.

Sounds like half a rebuild time. I'll call SRAM and see if I can get the parts needed.

CDtofer--I appreciate your comments concerning PUSH, they're a great company, but I still won't drop $150 into this fork. I'd sooner put that money towards a replacement down the road.

Thank you all for the help.
 

·
ballbuster
Joined
·
12,718 Posts
YEah, exactly

Lugboot said:
So, you're saying this will still happen with NO air pressure in the fork? I guess I assumed that if no air pressure was in the fork, then the full fork action should occur. That's what is confusing me.

Next step is to do what you suggested before (thank you), and tear the fork apart and replace seals again. Man.
Something is definately wrong with the spring side of the fork. Just take it apart. It's not that hard. Download the service manual from the Rockshox website. The 26er Reba diagrams will do if there is no 29er diagram. They work the same.

It sounds like you have some sort of interference inside the fork... like a part broke loose inside?

Actually, try this: Bleed off all air pressure from the positive and negative springs. Remove the left top cap to the air spring. IIRC, it's a 24mm hex if you have a socket that big. Do this in a clean area so you don't get any bits of fuzz or dirt in there. NOW try moving the fork. It should move with only the resistance from pressure or vacuum from the negative spring. Be careful when putting it back on. It doesn't have to be super tight, but all the surfaces have to be super clean, and the o-ring has to be lightly greased or oiled.

IIRC, the local shop here (Hank and Frank in Lafayette, CA... excellent shop!) charges like $50 for a Reba rebuild. Check with your LBS. I mean, what... you going to toss it in the trash? Worst case, you spend some dough rebuilding it and then you sell it for more. Better than trashing it. Heck, if you're going to trash it, I'll take it.

BTW, its a great fork if you get it set up properly. Do a search for Rainman's setup tips. Basically, use way less pressure than the sticker says, and its nice and buttery. Some folks on this board feel its a better fork than the Fox. I've never owned a Fox fork, but I'm perfectly happy with all three of my Rebas (one 26er and two 29ers) apart from the 29er version being a bit noodely.

*edit*

Oooh, I didn't think about the space between the lowers and the damper. Yeah, take the lowers off and see if a bunch of oil comes out of the right side. There should only be like 5 CCs of oil in there, which is like a thimble. If a bunch comes gushing out when you separate them, there's your problem.
 

·
HopHeads, Unite!
Joined
·
395 Posts
Discussion Starter · #17 ·
I definitely will tear it down and rebuild it--I've done it before. I'll check both legs as described by everyone in this thread.

When it's working correctly, the fork does have nice action. The part I cannot abide is how flexy it is. Until I can replace it, I'll run it. Until I can rebuild it, I'm putting a Niner rigid fork on the bike.

Thanks for the tip on how to check the air leg!
 

·
Registered
Joined
·
24,083 Posts
If your hub will allow it, try a DT RWS 9mm skewer to help stiffen it up a bit ;) :thumbsup:

Lugboot said:
I definitely will tear it down and rebuild it--I've done it before. I'll check both legs as described by everyone in this thread.

When it's working correctly, the fork does have nice action. The part I cannot abide is how flexy it is. Until I can replace it, I'll run it. Until I can rebuild it, I'm putting a Niner rigid fork on the bike.

Thanks for the tip on how to check the air leg!
 
1 - 20 of 23 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top