Gravel roads 'shake' you to great spots! HELP

[larrie]

Trial and error. I ran them around 75 psi for a while and the van felt like it was bouncing down the road. Dropped the pressure down to around 6p all around and then settled on 55/60. It rides comfortably and handles well at freeway speeds with those pressures.

[Otter]

Thanks. I'll give that a try.

[Scalf77]

Originally Posted by Otter

Larrie, I’m interested in how you decided on those numbers (55/60 pavement). I have the 285/17 KO2’s and have been trying to determine what a softer-but-safe pavement ride should be be. I’m at about 7500 lbs, almost evenly distributed front and rear (rear = +50).

This is a tire pressure calculator that is based off of information you can find on the tire ( Range, Index,rating) and front and rear axle weights. It also has a margin field, this is generally a good place to start.






-greg

[Otter]

Thanks Greg. It looks like I’ll need to open this on something other than my IPad. Will give it a look when I get to my Mac.

[Vanzila]

Slow Down and Air Down.

[arctictraveller]

Originally Posted by Scalf77

This is a tire pressure calculator that is based off of information you can find on the tire-greg

Could you please explain what "margin" refers to? Thanks.......

[larrie]

Greg, Thanks for posting this. It shows I am a little under aired on the rear. Will stop by the scales the next time I fully load it to verify the weights. Lucky there is a state run scale a couple of miles away that is on my way out of town.

[Scalf77]

Originally Posted by arctictraveller

Could you please explain what "margin" refers to? Thanks.......

Margin is a percentage of the per tire rate based off of axle weight, so if you want 10% margin than it will add 10% of the weight to the tire position, and increase the suggested air pressure. So setting to zero just calculates off of the axle weights. I normally give myself 10% margin, I think the tool had 20 as the last input I tested.

So it is just as safety factor that you can add in, to the equation.


greg

[OurayMark]

Shaking and rattling were the biggest problem with taking our 4x4 SMB off-road or on washboard roads. At the Overland Expo in Flagstaff I saw a solution at the Agile Off-road booth. They showed me the new “bead grip” wheels by Method which help keep the tires from debeading when aired down.
I bought a set of those wheels and based on advice from Agile I now air my 7500 pound van with BFG KO2s down to 25 to 30 psi on washboards. The lower the pressure, the less my expensive SMB gets shaken apart.
I air back up quickly for the highway using an ARB twin compressor.

[flybikeski]

We spent a week in Utah's San Rafael Swell on sandy roads with about 20 psi. Not only more comfy but we made it across some deep sand when I bet we would have gotten stuck with firmer tires. I just searched and saw a Jeep thread that had many guys running 10 psi without "beadlock" or any special rims.

Of course a Wrangler weighs a LOT less than my Sprinter so maybe 10 vs 20 is about right.

Ney
Fifty Classic Adventures – Epic Journeys for Active Families