Towing off-road trailer in SAND

[INSAYN]

This is not nearly as scientific as INSAYN's test. But I have a pop up trailer I pull down on to the beach at Lake Mcconnaughy in Nebreaska. The first year I had 5.30 - 12 tires and it sliced into the sand and was like trying to pull an anchor across the beach. Upgraded to 175/80-13 (hugh I know, but 2 to 3 times wider) and it pulled much nicer across the sand. Granted not the same beach, but I could feel the difference.

Perhaps some of the difference we are talking about is the lighter big tired offroad trailers don't need to air down because they already have such low footprint pressure it doesn't matter, but in more conventional tired trailers it is more important.

I've driven on that same stretch of sand at Lake McConnaughy in my one ton diesel crew cab/camper combo. That sand is awesome stuff.
I went out there weighing in at ~11,500lbs for truck, camper, gear and family of 4 with the tire still at 80psi. Did fine until I stopped, I knew this would happen, but wanted to see how far I could press my luck.
Dropped the fronts down to ~30 psi, rears to ~35 psi and this was enough to pop up back on top of the sand to easily get back to the highway. This is where we stopped before airing down.
Fun lake, going back next summer to kayak fish for Walleye! Sorry for slight hijack. :sombrero:

 

[XJINTX]

As Jason stated we will experiment and see what is best for each of us.

Wish I new exactly how much my trailer weighed full!!!

 

[theicecreampeople]

ya roger we will do another test on th smitty built trax ....either was the beer is cold and have two boys to dig us out ....were two old to dig roger ..lol..

 

[grimbo]

Airing down your tyres isn't about widening your contact patch but lengthening it. I've always used tall skinny tyres aired down and found them to work better than an aired down wide tyre. In other words my 33x10.50 worked much better at low pressures compared to my 33x12.50 at similar pressures. Same goes for the trailer in my experience

 

[theicecreampeople]

well wish i had more for you guys ,as i said we would do one trailer aired up and one aired down ..i stayed aired up ,xjintx aired down ,the only problem was we had no issues , ..if we had more time we would have done a major test until one of us got stuck ?kinda wanted the jeep to get stuck ..lol..lol..so i could pull him out with my toyota ..so whom ever wants to take the next challenge and do the test would be cool to find out ....jason ..

 

[kevint]

Did you stay primarily on the hard sand or did you drive back by the dunes too?

 

[theicecreampeople]

Did you stay primarily on the hard sand or did you drive back by the dunes too?

ya bro our trip there took alot longer so we only made it to marker 15 i think ,we unloaded and set up camp ...my trailer had a rtt on it so didnt move the weekend ...but was a busy weekend and there we pretty packed roads by that time ...

 

[medic83]

Ive been to Pismo dunes a bunch. This was the first time Ive towed a trailer there. I aired the trailer down to 17 PSI. We went way back into the dunes as it was Memorial day weekend and it was windy so we wanted to find a low wind, and private area. My trailer did great! Just keep up momentum, dont stop on a uphill. You want a fat balloon tire to float. I took it into the soft deep stuff and had no issues.

 

[98roamer]

Being from the somewhat midwest, I think of it as a farm tractor pulling a plow. Is it harder to pull a plow cutting into the dirt or a sled sliding over the dirt.

Being easily confused, I need simple but exaggerated illustrations to fully grasp complex issues. But pictures are my favorite.

 

[mrchips]

I have pulled my AT Chaser across sand and never air down as the tire pressure is 17psi for normal driving. It is a 33' tire and the trailer weight combined is around 1300 lbs, so don't need ATTACH=CONFIG]102987[/ATTACH] much tire pressure as it is.

 

[teotwaki]

I have pulled my AT Chaser across sand and never air down as the tire pressure is 17psi for normal driving. It is a 33' tire and the trailer weight combined is around 1300 lbs, so don't need much tire pressure as it is.

A lot of us are running very average sized tires on regular 16 inch rims and the tires' normal pressure is 32 pounds

 

[cnynrat]

A lot of us are running very average sized tires on regular 16 inch rims and the tires' normal pressure is 32 pounds

Sounds familiar. I am running 255/85R16's on my Horizon. I normally run about 30 PSI on the road, and air down to 18-19 PSI for the trail. I've not done a lot of running in sand, but I did pull it through the western end of the Mojave road past Afton Canyon without any problems.

My instinct would be to air down more in deep or soft sand if I needed to.

 

[INSAYN]

The rule I use for airing down any tire regardless of the weight it is supporting goes like this.

At highway pressure, and on a hard surface, measure the distance from the ground to the lower edge of the rim.
Say it's 8" for the sake of easy to understand math.

Now, start letting air out until you have reduced this distance by 25%, which in our case would put the rim 6" off the ground.
By doing this, you have now increased your foot print by 200%.

Airing down this way keeps me from "picking" a pressure and reducing to that, where actual tire contact is more important.
Meaning that one day I may have my right rear and left rear really close to the same pressure just by luck, and another day depending on my current load both tires could be different pressures but have the same sized contact patch.

So, in a nutshell it isn't the tire pressure that matters as much as the contact area. Reducing rim to ground distance at the same ratio for all tires regardless of supported weight on that tire will give optimal results.

You can certainly go more or less with this depending on your needs, but do them all the same way and don't pay attention to the pressures specifically as you will find each tire could easily have a different pressure.

 

[mrchips]

How are you making the determination as to what tire pressure to run. I use chalk with the trailer loaded, make a line across tread, then roll it over a few revolutions and look at chalk line. With my trailer and weight I came up with 17 psi and I have good contact pattern and no wear problems. Do the same with Jeep, and on 35's my street pressure is 25 psi.

 

[grimbo]

I just use the 4 psi rule. If after an hour of driving my tyre pressure has gone up by more than 4psi it has not enough air, if it hasn't shifted too much. You soon have an understanding of pressures for different circumstances and can then tweak from there