Fox 40's sagging when lowering air pressure

EsPeGe

Likes Bikes and Dirt
Hiya burners, I hope everyone is getting their time on the saddle in with the end of daylight savings fast approaching. So I have questions......

I'm trying to get my Fox 40's set up after removing 2 volume spacers. I'm going back to factory settings as a start point and am trying to get my sag set correctly. Now, as I reduce air pressure from the 69 PSI suggested to 60 PSI the forks settle noticeably by about 5-8mm. To test this I pushed the sag ring all the way down and pumped the forks back up and then checked the sag ring again. Yep there was a gap of about 5-8mm between the O ring and the fork seal. Now I know that when I let air out completely to remove the volume spacers the forks dropped considerably but I wouldn't expect they'd do this still at a normal riding pressure. Then I have to physically lift the bike and pull the forks out to full extension which seems odd. Should I be measuring SAG fully extended or where they sat originally? Am I losing some travel here and most imoportantly what could be causing this? I followed Fox's instructions to a T when I removed the spacers so I can't think of why this would happen unless there is a vacuum somewhere or too much pressure in the negative chamber maybe??? Whilst I can do basic fork services the inner workings are voodoo to me so any help is much appreciated.

Cheers team, Scott.
 

shmity

Likes Bikes and Dirt
Cycle the forks as you let the air out. There is a dimple in the stanchion that allows air to transfer between the positive and negative chambers to equalise the pressures. As you let air out you're effectively increasing the negative air spring pressure comparative to the positive which will suck the fork down a bit. A few cycles of the fork past the dimple (which should be around sag point) will allow the pressure to re-equalise and you're good to go.
 

EsPeGe

Likes Bikes and Dirt
Cycle the forks as you let the air out. There is a dimple in the stanchion that allows air to transfer between the positive and negative chambers to equalise the pressures. As you let air out you're effectively increasing the negative air spring pressure comparative to the positive which will suck the fork down a bit. A few cycles of the fork past the dimple (which should be around sag point) will allow the pressure to re-equalise and you're good to go.
So no joy mate. Still doing it. I started from scratch, removed the air completely, removed the top cap, reinstalled the top cap then pumped them up. No luck fork is still sitting with 8mm or so of travel that can be pulled out when the bike is lifted up and the wheel pushed down. I thought that maybe I had a vaccum in the negative side but if this were the case when I pulled the wheel out it would pull straight back in. This doesn't happen, when I pull down on the wheel it stays out.

So I pumped it way up to like 100PSI (120 is max) and tested it there. The amount of travel that I could pull out was less, it was down to about 3mm. When I dropped the pressure down to my settings it was back to 8mmish.

Then I dropped all the pressure again and then followed the 2019 X2 shock procedure of putting a little air in, cycle it, put more air in cycle it and keep going like this till desired pressure is reached. Still no luck. I've heard that if there is a smidge too much slickoleum it can block a port making it difficult for the fork to equalize. At this point I can't think of anything else, any help or suggestions are appreciated.

Cheers Scott.
 
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