How low can you go?

I am running 33" TA radial Mud Terrains on my Jeep. I usually run them at 20 psi which seems about right for the light Jeep.
I was wondering how low I can air down (for trails) and not risk slipping a tire off of the bead. Anyone have any suggestions?

 

I run my 31x10.5 at 10-12psi in the rough stuff, haven't popped a bead yet.

 

Back when I had my 67 Jeep, I had tubes in my tires would go down to 5-6 lbs

 

Thanks Mcruff, I'll give that a try.

 

Not sure if tire width would affect this at all or not. you didn't mention how wide your boots are. I am running 33 x 9.50's and usually drop to 18 - 20 psi. I would like to drop a bit lower, like 15 psi but never tried it. I would think a wider tire would fare better with lower pressures than a skinny would but, I'm just guessing.

 

It does matter how wide of a wheel you have. Let's say you have a 33x12.50x15 tire. It's more likely to come off the bead of a 10" wide wheel than an 8" wide wheel at the same tire pressure because the side walls and beads are being stretched farther apart on the wider wheel.
I run the above mentioned size tires on 10" wide wheels and usually air down to around 12-14 psi. but I also watch my turning and what not real close. It also matters how "tight" the bead of the tire fits onto the wheels. Some are tighter than others and that can affect how well they stay on. Mine fit very tight.

 

I know when they mounted my tires, on 15 x 7 rims, they had a hun of a time getting them to seat. I think the rims are actually a bit too wide for the tire. 15 x 6 would have been better. I figure if they had that much trouble seatinr them, I would have even more if I ever popped one off the bead and that they might come off easy if they were that hard to stretch onto my wheels so, I run them a bit fuller than I would like. Sorry if I'm hi jacking.

 

I run a 33x12.5x15MTR and air down to 10 on a 10" rim , never have popped one yet but they fit tight in the bead. every now and then I might here a phhhht and just figure that tire felt it needed to air down some more..... i do some crazy stuff sometimes .

 

Nope, not hijacking. fits right in with the topic.

 

I run my 35 12.5 15's at 12 psi offroad. When I was working on it, I thought they looked a little low: checked at 7 psi. Anything above 10 the look fine the jeep is so light. I haven't dropped any lower yet because of concern for difficulty steering, but may try 10 my next outing. I was amazed at the noticeable difference in ride from 14 psi dropping to 12.

 

I run 33-12.5 KM1's on 8 wide wheels at 8 psi-so far no problems and have been considering going to 6 psi. Hazel probably has this wired?

 

I usually run 8-10 psi on mine on tough trails and 6 psi in sand. 33x10.50 on 8" rims.

 

i run on my cj6 with hard top 33x9.5-15 on stock wheels and i never have more than 8 psi offroad

gerald

 

OK, so what psi are you guys running on the street? As stated before, I am running 33-10.50-15's on 8" rims at 20psi. (flat fender w/fiberglass body)

 

25 normal running but 35 to flat tow

 

The best way to know is:
1. draw a line across the tire (something you can see)
2. drive a straight line down the road, after some distance check the line

If the line is worn off in the center, too much air.
If the line is worn off on the outsides, too little air.
The line should wear off evenly across for the correct pressure in YOUR rig.
I'm going to guess that you're close at 20psi.

As for Off road:
trails: 8
sand: 6-8
snow: start at 5 but down to 3 pretty fast, sometimes lower

 

On the street i run like 28 psi up front and 25 in the rear. Soft top and I usually don't have anything in the JEEP except me and an iced tea.

 

Thanks,
I'll give it a try as soon as the snow clears