[Lelandjt]

Crosspost from the Tech forum cuz it wasn't getting any activity there:
I'd rather not take apart my 08' 888 ATA just to figure it out so I'm hoping someone who has can explain it to me. When you make pressure changes to the main air chamber it affects the pressure of the PAR chamber and vice versa. Is there a floating piston seperating these chambers or what? I don't need to know how ATA works but a better understanding of the relationship between main air and PAR would help me in tuning. Right now I'm running 70 in main and 100 in PAR.

 

[bullcrew]

Crosspost from the Tech forum cuz it wasn't getting any activity there:
I'd rather not take apart my 08' 888 ATA just to figure it out so I'm hoping someone who has can explain it to me. When you make pressure changes to the main air chamber it affects the pressure of the PAR chamber and vice versa. Is there a floating piston seperating these chambers or what? I don't need to know how ATA works but a better understanding of the relationship between main air and PAR would help me in tuning. Right now I'm running 70 in main and 100 in PAR.

Dont know what your weght is but Im 220 and trying 90/120 and prbably will go 100/130 and adjust the air volume on the left side to fine tune.

I know ata has to be 30psi less than the par chamber, if its 130 par then ata has to be no more than 100. It can be greater than a 30 pis difference though.
I know not much help just some info I picked up from Marz.

 

[BrooklynMachine]

We were told that PAR pressure was recommended to be 30pi over but can also be equal to the main chamber pressure, just not below.
We ran ours 75main/100 PAR yesterday. Average rider weight was 200lb loaded and the zip tie definitely showed full travel was used.

 

[davep]

Floating piston between the two chambers. The piston is litterally tied via string to the bottom of the fork leg, so the volume is limmited and pressures can be differentiated. If the piston was truely free floating, the pressures would be equal.

Top chamber has lower pressure and compresses against piston (air pre-load) untill pressures are even and the lower (PAR) chamber starts to compress as well.

 

[bullcrew]

We were told that PAR pressure was recommended to be 30pi over but can also be equal to the main chamber pressure, just not below.
We ran ours 75main/100 PAR yesterday. Average rider weight was 200lb loaded and the zip tie definitely showed full travel was used.

it can be equal but Ronnie suggests min 30psi or more pending rider style weight and terrain.
either way theser forks are sweet!

 

[ZEDMAN]

ive had the fork for awhile now and i never really understood what the red knob under the black rebound knob does....anyone?? also im not getting full use of my travel, maybe an inch shy......

 

[Kanye West]

There is a floating piston near the bottom of the ATA cartridge. It's held on by this super ghetto looking tether. They made the whole ATA cartridge a tiny bit longer this year so it won't limit the travel until you're actually at bottom out. I haven't experimented much yet with anything less than a 30 psi difference, but if anyone can confirm that it WON'T damage the floating piston itself I'd want to try maybe a 20 psi difference. The last time I saw someone try to run equal pressures in an '07 ATA the PAR came out mangled.

The red knob just threads down a cap near the top of the damper leg and effectively makes the air pocket on top of the oil pool smaller. It really doesn't affect the preload as much as the progression of the fork, but the difference is so miniscule that you won't notice it unless your oil level is already almost at the brink of making the fork hydraulically lock near bottom out.

 

[Lelandjt]

Thanks, this info on the tether was exactly what I was looking for. I figured there was something going on there besides just a floating piston.