Just done a long overdue lower leg service.

When I put air in the neg chamber, it’s sucking the fork down before I get close to the pressure in the positive. Can’t say I’ve noticed this before – do I have a problem, Houston?

Set the pressure you want then measure the amount of top tube showing. If you’re still at above your max travel (150mm I think), then it’s probably fine.

The whole point of the negative air spring is to such the legs down a bit and sit in a sort of neutral position. It’s when they suck down too far that you have a problem (ie, air moving from positive to negative).

When re-assembling the forks make sure the air shaft is fully extended when putting the lowers back on.

I once re-assembled with the air shaft at ~50% and could not get the forks to behave correctly, I was loosing a lot of travel.

Took the lowers off and tried again, but this time taking care to not compress the air shaft too much and they fine after that.

Hey I had exactly the same issue and found a kind of fix although they are still not quite right:

http://singletrackworld.com/forum/topic/rev-u-turns-sucking-down-after-service

jairaj – good tip there, I suspected that may have something to do with it so am going to give it a go tonight and see if it improves things!

An update to help anyone else in with the same issue.. I did as suggested and ensured that the air piston was fully extended before pushing in the air piston base cap and circlip. I also wound the Uturn down to min travel before installing the top cap. Afterwards I wound out to max travel again and put the lowers on. Result: perfectly working fork again!!!

I did as you suggested and there’s an improvement, but I’m still about 5mm down. I’ll probably leave it at that until they go off for an upper service.

I didn’t do any messing with circlips and the like.

Cheers!

BTM