Fox Float Evols - do I have this right for adjustment?

[StinkyFingers]

Hey guys, Noob post I know but I have the xtx with the evols and no manual. For adjustment I see there are 2 valves on the chambers (top/bottom). I assume the top valve is for the main and the bottom ones are for the piggy backs. Is that correct?

Probably about 215 lbs w/gear on (thanks to the holidays) and I sometimes have a 10 year old on the back with me (130lbs).

Hoping someone can give me a ballpark psi to set each of the 4 shocks (2 x skis, 2 in skid). Garage is not heated so figure on my adjustments done at about 32F (0*c). And do I do use valves on each shock?

Thanks !!

 

[Mike P]

Make sure the sled is off the ground when setting air pressure. I do not run air shocks so I am unable to give you any information with respect to pressure required.
One other point might be that the 130# load will make the sled handle very different if you set up for it either way. Probably want to set your gear for yourself and just take it easy when the little guy is on the back.

 

[Wannaviper]

I copied this out of the owner's manual, I believe it is for the front shocks:

"The air pressure in the EVOL air chamber is adjusted to control the vehicle corner roll and bottom-out characteristics in the last 1/3 of shock travel. The pressure in the MAIN air chamber is adjusted to change ride height and the suspension stiffness of the snowmobile."

Reference Air Pressures

EVOL Air Chamber Main Air Chamber

Mountain/Backcountry 120-150 35-65

Performance/Trail 160-180 35-95

Sno-Cross/X-Country 200-250 100-120

 

[Mtnviper]

Typically you will get your best ride quality when you set the EVOL chamber to 40% to 45% more then what your running in the main chamber. There are exceptions to this of course, depending on terrain, riding style, etc.
For example,
65 psi main + 40% = 91 psi in the EVOL chamber.

 

[StinkyFingers]

Thanks for the info guys.

 

[PeeWee86]

I can’t comment on the rear suspension. I am running coil over shocks in the rear. After a lot of experimenting and I am using 62 PSI in the main chamber and 110-115 psi in the EVOL in my front shocks. This is a substantially higher difference than the 40% that was recommended above.

 

[StinkyFingers]

Ok just confirming again, haven't had time to look into it more. Top valve on the Evols are for the main shock and bottom valve is for the chamber right? That said I'm more concerned what I should be setting the 2 rear shocks in the skid at.

Front Skid Shock: Main PSI at xx, Evol champer PSI at yy
Rear Skid Shock: Main PSI at xx, Evol champer PSI at yy

 

[InRBigness]

Okay I have the same set up as you. .

First: to adjust the shocks, begin at the beginning. Lift the front sled into the air. Begin with the front shocks let all the air out of the main chamber. Fill the evol to desired level. Once there, adjust the main chambers. The main chambers are what set the right height.

Next lift the back off the ground and release the main chambers. Set the evol chambers then set the main chamber on the rear skid shock to set ride height. Then do the same with the front skid shock.

Back ground Knowledge:

So, the more you put in the front skid shock main chamber the lighter the steering will be as it takes weight of the ski's. I have not noticed it makes the ride any harsher
My rear skid shock main chamber allows my sled to have about 1-2" of sag sitting without any rider on it. It also allows a fairly good recovery from big bumps. Rebound is also adjustable but I have not played with it really.
Setting outside is the best for truer values as when the shocks get cold the pressure lowers but that involves some other issues like lying in the snow, chance of water/ice getting into the valve (small issue). I do mine in the garage and add 10psi to compensate for outdoor temperatures.

From what I can remember my settings are:

Evol Main

Front 180 110 (or where ride height is correct)

F Skid 200 160 (or where steering is wanted)

R Skid 200 125 (or where ride height is where I want it)

I am 250lbs dressed and carry a rear bag with about 30lbs in it on my tunnel.

Always empty main chamber, inflate Evol then adjust main chamber. Rinse and repeat. Sled has to be off the snow to get true readings.

 

[StinkyFingers]

Now it's all making sense. Thanks so much, much appreciated.

Edit - I should stick to using this forum via computer and not my phone. It appears I had missed a couple posts above. Thanks everyone for the help. Once I get it all tweaked I'll report back with my findings/psi's