help -rebound failure

[Bos]

My RS Revelation air U-turn has been leaking a little oil from the right top end of last year, I would notice a little bit of oil around the gap between the lockout leaver and the crown. So when I went to California I left the Fork at LBS, they serviced it and  replaced seals (nothing to do with that I know)

So Ive been riding it again for the last 3 weeks and noted same thing, oil on the right cap. When noted to my LBS they mentioned a Cartrage might be blown (sounds expensive)

 

So I was just cleaning my bike now, and wanted to set my fork up properly since It felt a little slow on the rebound since the service.

So I thought Id turn the lockout on full to make sure it works 100%(cause that should suck the fork down and return very slow If it works fine.) I then Turned the know towards the little tortoise on the leg to slow it down.  But in sted of it slowing down the rebound it felt faster?? Now I was confused. So I turned It back the other way ( It was now turning quite easy and didnt really feel like it was turning much inside) and when all the way to the hair picture, It felt exactly the same

 Oh well. I thought, Since Im quite light and set my fork up quite soft I normally leave the rebound on minimal anyway.

 

So I continued to the other side letting out all the negative air which did splurt out some tablespoon of grease+ oil which got a drop on my disc (I was holding a piece of paper beteen the two but the sheer amount of oil overwelmed me )anyway so I took the wheel out and rinsed the disc with boiling water and scrubbed it with sunlight and a scourching spondge.

The bike was tuned upside down for this.. so I flip it bac kon its rubber and to feel what it feels like after the settup I give it a squish but now there is no rebound.

 

I noticed a little bit more oil has come out the right top, but this was not even a ml, so could not have had that kind of effect on the performance.

 

So Here I sit, One week before the xterra and no rebound..

[Bos]

heeealp

[leet22]

My Physlo has same probs so also would like to know what is wrong.

[Bos]

When I turned the fork upside down, some oil just freely flowed out of the little hole where you insert the allen-key to adjust the  lockout-platform , I left it open because I thought adjusting that might have had someting to do with it.

 

So Could it be that the cartrage has blown and now all the oil is either "left the building" or is somewere else in the fork?

 

 

[droo]

Sounds like a case for Detectives Bornman and Lefty. Good luck getting it sorted, I'd start by getting your LBS to have a whinge at the service agents (since they were the last ones to fiddle with it) and see if they'll loan you a spare for the weekend.

[Johan Bornman]

I can't picture the Revelation in my mind right now but in my experience, none of the modern RS products have cartridges. They're all open bath designs. Further, the rebound mechanism is at the bottom of the stanchions so if oil leaked out, you'll first loose compression damping (test yours please by engaging lockout, and then as the oil depletes further, rebound damping. In other words, if you still have lockout, there is enough oil for a healthy rebound damping system to do its job.

 

The rebound damping is a very, very simple system comprising one needle valve (that you turn at the bottom) and one return valve or shim. If yours turns but does nothing, the connection between the knurled knob at the bottom and the needle valve is somehow compromised. Broken, stripped or whatever.

 

The stanchions must come out of the sliders, the right stanchion must be opened at the bottom (and top actually) so that you have access to the rebound damper piston and it must be inspected.

 

You need to do a Fork Service Workshop so you're no longer at the mercy of mechanics who flaunt fancy words.

[Bos]

You are right Johan, I need the service workshop 4 sure, when Is your one near Argus time? I would dog to come to that one.

So Heres what happens.....

 

On your first Question.. the lockout stil worked fine. which is weird, but hows this..

I was bust sorting my bike to go do a training triathlon in Tokai when this happened so I yust went anyway, broken fork  and all ,thought I would just not ride it to hard..

 

So I start riding it up a long smooth Climb and after 15 minutes there is a slight dip in the road, At this I get up  and feel the fork which was a pogostick with no damping. Upon one of the compress and pull up actions, It tops out loud , and then guess what..

 

Suddenly the fork packs down and returns slowly.. I stop and turn the rebound to the - side and to my pleasent surprise My rebound's back!

 

How you explain that one, hell knows.. It is still leaking oil out the right top though.. Johan, What needs replacement?

Any Ideas on the rebound phenomina? I would obviously like to get it sorted as I really done like "ghost- dampning"

 

Anyway, I had a cracker of a ride.. Noticed theres no one in tokai around 2-3pm.. duno why.

 

[Johan Bornman]

You are right Johan' date=' I need the service workshop 4 sure, when Is your one near Argus time? I would dog to come to that one.

So Heres what happens.....

 

On your first Question.. the lockout stil worked fine. which is weird, but hows this..

I was bust sorting my bike to go do a training triathlon in Tokai when this happened so I yust went anyway, broken fork  and all ,thought I would just not ride it to hard..

 

So I start riding it up a long smooth Climb and after 15 minutes there is a slight dip in the road, At this I get up  and feel the fork which was a pogostick with no damping. Upon one of the compress and pull up actions, It tops out loud , and then guess what..

 

Suddenly the fork packs down and returns slowly.. I stop and turn the rebound to the - side and to my pleasent surprise My rebound's back!

 

How you explain that one, hell knows.. It is still leaking oil out the right top though.. Johan, What needs replacement?

Any Ideas on the rebound phenomina? I would obviously like to get it sorted as I really done like "ghost- dampning"

 

 

[/quote']

 

I have no doubt that a new set of internal O-rings will cure the strange behaviour. You have air leaking between chambers and oil going where it is not supposed to go.

 

The erratic rebound damping sounds like shim with dirt in and stays open from time to time. Inspection and clean.

 

The oil leaking from the top requires a new O-ring on top. Remove the Poplock (if there is one on there), by first removing the Gate adjuster knob, then the Poplock pulley or knob. Now you'll see a 24mm (maybe 26mm) Hex cap. Unscrew this and slowly pull out the Motion Control Damper. I've posted pics of this before so search for Motion Control under one of my posts.

 

No need to completely pull it out. Just enough so that you can remove the top O-ring. Get another one like that, fit it and return everything as it was. Should take you ten minutes and a trip to the O-ring supplier. It is a standard metric O-ring and readily available.

 

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[techguy]

Check the top cap of the cartridge is tight, I had that on my Reba, most of the oil leaked out thus affecting the lockout, and rebound, the rebound worked from halfway thru the tavel...The O-ring may be fine but if the cap is loose the o-ring can't do its job properly...