Looking for some expertise from the revelation aficionados on STW !
I have just acquired a second hand set of 2011 dual air RLT's which the seller told me he had been running at 130mm travel but that he had just got changed to give the full 150mm.
Two queries -
1. How do I find out if I can get the full 150mm travel ? Despite running low pressures on the trails I wasn't getting anywhere near full travel. I have also tried letting all air out ( + and - ) but still can't get the forks to bottom out (probably only getting 100mm of travel or so).
2. When I let air out of the -ve chamber manually should oil be coming out as well (it is when I do it !) ?
Cheers
G
1: Let all the air out of the neg then the pos. Jump / press on the bars: you'll get full travel with a moderate amount of pressure.
2: Normal.
There is a "common" issue when damping fluid leaks past the lower inner damper seal into the lowers. This stops the fork getting full travel (hydro lock).
As a diasnosis: if you unbolt the damper side bottom bolt a few turns (not totally unscrew it), then tap it upwards with a rubber mallet, you may see the tell tale blue fluid leaking out (or any colour other than that from the air side valve).
Any more Q's just let us know.
To add to what couldashouldawoulda's said about the "hydro locked" symptoms: if you're not able to get a near complete lock out if you turn the damper knob clockwise all the way, then damper oil is low and has most likely migrated to the lower right leg. Faulty o-ring is usually the culprit. Easy enough fix if you're comfortable with DIY lower leg service.
Thanks guys. I have let all the pressure out and am still a good 50mm away from full travel. I will have a look at the damper side tomorrow and see if it shows signs of what you say.
Bit disappointing as the seller apparently put the forks into his LBS to get the travel reducer shim removed so you would have thought they would have spotted this......
As mudsoul says it's an easyish fix if you're a half competent diyer.
It's also really a good idea to learn to drop the lowers on these (basically a mini-service: just a clean, oil and foam ring stuff).
So I'd say get those lowers off and see if there's anything else amiss.
Just to clarify:
1/ In terms of 150mm versus 130mm, this is done with a 20mm all travel spacer fitted in the air spring side of the fork. This is removable, so you can set the fork back to 150mm.
The available travel is roughly equal to the space between the seals and the crown. If the all travel spacer is fitted, the fork will have about 130mm (plus a couple) of stanchion showing. Removing the spacer will expose 150mm of stanchion, lengthening the axle to crown and slackening the bike about a degree.
The all travel spacer limits spring extension, so the fork start off lower, so you 'loose' travel at the start of the stroke, it should still be able to push through to the end of the stroke.
This is different to if the fork is unable to use all the available travel. If the seals are stopping short of the crowns (whatever the travel is set to), which sounds like the issue you have, I'd suspect hydro locking as above.
Spring is left leg, damping is right leg so possibly completely independent issues.
A quick check is as couldashouldawoulda says but if they have been serviced oil colour is not a give away. There should be about 15ml of lube oil in there - any more indicates the damping oil has migrated downwards.
2/ You ask about oil coming out of the negative air spring valve. This is nothing to do with the damping circuit, the damping is in the other leg. There is a small amount of lube oil in the air spring and it's usual for the negative air valve to 'spit' a bit of oil when depressurised. Use a cloth to ensure you don't get it on the rotor.
I think too much oil in the compression damper can also cause this!
I could be wrong but I think there is different volumes on different year forks and dampers.
I have experienced issues before and I guessed I had a hydrolic lock due to overfilling the damper.
You can check this by taking the damper out and compress forks. (Once you have turned upside down and collected the oil) if you are doing this make sure you have some new oil in the right weight, ready to replace it with.
There maybe too much lube oil in the lower legs. Rock Shox only recommend 3-8 ml of oil in the lowers for lube. I, like many others, add a bit more to make sure there is plenty of oil splashing around to lube the bushes/seals. I tend to put about 15-20ml in and accept a 10-15mm loss in full travel, but am happy to know my forks are getting well lubed (7 years and no worn stanchions) Hope that make sense, had a few glasses on vino 😉
20ml of oil in a fork lower is going to be under 2mm deep so if you've lost 20mm travel there is something else up. 😉
thanks for your thought chaps. Time to refer to seller and see what he is prepared to do