i have recently got a pair of 07 revelation dual airs, and having tried various pressure combinations (having read past threads on here) have failed to find a set up that doesn't end up with the -ve pulling the fork about 5-10mm into its travel, any ideas anyone? i weigh about 80kg kitted up and am running about 110psi in both chambers to give about 25mm of sag
cheers
will

They do that, try 5psi less than the +

i lose around 3-4mm of travel and if i put less in negative or more positive thet top out

I found completely emptying the -ve before filling the +ve; then filling the -ve helped.

cheers guys i'll give it a go

I found completely emptying the -ve before filling the +ve; then filling the -ve helped.

How can this make any difference?

FWIW your "problems" are just a facet of how these forks work.

It does make difference Mr cynic, since if you fill (or top up) the -ive chamber first you reduce the size of the +ive chamber and thus the same pressure in the +ive is actually less air than if you hadn't filled the -ive first.

Of course if you keep putting air in the +ive side until the forks are fully extended and then reduce it to the correct pressure all should be the same (except you've probably now got too much pressure in the -ive side since you've now compressed the -ive chamber).
Overall, it's just easier to make sure you fill the +ive first.

Cynic-Al FAIL 😉

glenh is right.

As has been suggested above, empty both chambers, fill the +ve then the -ve. If you're still getting travel loss (and actually care – it's only a few mm and isn't really lost travel as it just affects the sag) then start again and reduce the -ve by 5 psi compared to the +ve.

I find they work better with a bit more -ve pressure even if you lose a few mm of travel, especially on a full sus as it feels more balanced with the rear.

HH – You mean you like them with more sag because that's what that does…

yes, although the 'lose a few mm' comment was referring to above where you lose a bit of travel even when theres no weight on the forks.

That's what negative does, pulls them into their their travel to get 'em moving. Also I like them coz you can make the fork match the rear shock feel really well. I love my Revs 😀