What's your AT tire psi/airbag psi/shock set up?

[coastsider]

I'm particularly interested in what psi settings and combinations you are running on your Horizon AT when fully or near fully loaded (2500-2700lbs total) on the following surfaces, I have 265/65/16 AT's on the trailer (my settings in parenthesis):

1. Sand (airbag 40psi, tires 15 psi)
2. Mild rock garden (airbag 20 psi, tires 20 psi)
3. Gravel/fire road (airbag 40 psi, tires 35 psi maybe one of the above if can't air up))
4. Freeway (airbag 40 psi, tires 35 psi)

I'm experimenting with these but would love to hear of experiences you have had good or bad. I of course air down the truck to an appropriate setting for the terrain as well.

 

[UK4X4]

weight changes trip to trip, I usually set my airbags at arround 1/2 their travel
rather than measure the PSI

As height V's PSI will vary weight to weight

ie 20psi gives you only 2" of height with 2000lbs

but would give more height if only 1000lbs was being carried

I don't change airbag settings for conditions as want to be mid travel all the time

Going forward I'll be fitting limiting straps and pressurising the bags against them for road use, ie to limit its movements while on the road

Tire pressure wise as per the truck

 

[coastsider]

I already have the limiting straps, a good addition for sure. I also have the Firestone airbags and think I'm right in saying the max psi is 100, with a max extension of 7"?

 

[johnsoax]

I could understand changing the airbag pressure to correspond to weight. I don't understand why you would change the tire pressure on the trailer. It isn't driving anything, it only needs traction to keep from sliding side to side as the vehicle is going to pull it. Am I missing something?

 

[coastsider]

I've heard arguments both ways, I'm guessing airing down for rocks would help grip? And sand would mean floating better over the loose stuff with a larger footprint.

 

[gabepari]

I could understand changing the airbag pressure to correspond to weight. I don't understand why you would change the tire pressure on the trailer. It isn't driving anything, it only needs traction to keep from sliding side to side as the vehicle is going to pull it. Am I missing something?

Lower tire pressure adds suspension travel... In both directions. Helps ALOT in the rocks. Don't want to "turtle" your trailer :elkgrin:

 

[johnsoax]

Lower tire pressure adds suspension travel... In both directions. Helps ALOT in the rocks. Don't want to "turtle" your trailer :elkgrin:

Thanks for the answer!!

 

[StumpXJ]

Lower tire pressure adds suspension travel... In both directions. Helps ALOT in the rocks. Don't want to "turtle" your trailer :elkgrin:

Please explain how this would add suspension travel?

 

[STREGA]

I have the same vehicle/trailer/tire combo as Coastsider. I have never weighed my trailer for a exact weight when loaded with all the camp gear but I don't think I get to 2500 lbs. I run about 20 psi in the tires even on the highway, much more than that and the edges of the tires don't make contac with the road. As far as the air bags go I run them at 6" (per AT?), seems to handle wash board dirt roads just fine.

 

[gabepari]

Please explain how this would add suspension travel?

Lower pressure, squishier tire... Squishier tires "squish" more when they encounter objects. More squishing of the tire translates into less required squishing of the spring, there-by leading to less relative movement of the trailer body. Bigger bump, trailer moves less... I say more suspension travel :elkgrin:

If you don't view the tire as an integral part of the suspension, then I guess its a hard sell... But the tire is indeed part of the suspension, on some torsion axle setups it might well be a majority of the suspension.

Gabe

 

[StumpXJ]

Interesting way to look at it I suppose. We will have to agree to disagree :beer:

Imho:

The tire pressure has zero to do with how much limitation (or free movement) there is on suspension components moving in a cyclic motion either up or down. When you say "adds suspensions travel in both directions", I think what you are trying to convey is the fact that a lower PSI in the tires aids the suspension in its dampening duties. (???) Its doesnt mean the tire pressure will allow for more or less physical up and down suspension movement.

In an effort to not get too far off topic, I used to run about 50psi in the bags with a fully loaded trailer, and 30 psi in the tires on the highway. On the dirt I would run about 30 in the bags.

Like I said, not trying to sway you opinion or anything, just trying to understand your thinking on the subject.


~ Stump

 

[coastsider]

I used to run about 50psi in the bags with a fully loaded trailer, and 30 psi in the tires on the highway. On the dirt I would run about 30 in the bags.

This sounds like a good set up to me, I'll try it in DV this week through Steel Pass.

 

[mrchips]

I run my Chaser tire's @ 18 psi 33x12.5x16, and inflate the airbags to a measurement of 6". this is the info Mario gave me, there was no PSi setting for the bags.

 

[gonejeeping15]

I like to provide an easy ride for whatever load I have in the trailer and maintain an even tire wear at the same time. If that requires 20 PSI, then thats where I set it.

You can spray WD 40 across your tread then drive forward on a concrete drive way and check your tread patern, just don't lower PSI enough to allow bead to break loose!

Doug, w6jds