Michelin XZL and wheel assistance

[bdelaporte]

I am wanting to run a set of 395/85R20 tires on my truck. I am having to get a set of custom steel wheels made as it came with 18x8 wheels and 12.00R18 tires and a weird 8 lug x 270mm bolt pattern. I have a couple questions that I am hoping to get some assitance on. Pretty much new to this size stuff, so bear with me. Thanks

First the truck specs/uses:
weight 9920 lbs
2.5 ton axles
I live in Florida, trail rides with mud and sand are the main uses
It is not a daily driver but will spend time on the road (under 60 mph with these tires and gear ratio) in order to get to the trail or mud bog.
The truck has CTIS (Central tire Infaltion System) on it and I plan to be able to air down when on the trail.

The Michelin military tire website states that these tires are to be mounted on 20x10 wheels.

Q1: Has anyone ran them on any other size such as 20x11? Is it possible, advantages/disadvantages?

The bead and sidewall on these tires seem very stiff. My truck is pretty heavy (9920 lbs) but these tires are designed for 9200 lbs or so at max capacity. I have read about a few guys complaining that they have popped these tires off the wheel while under torque or lateral movement while aired down.

Q2: Do I need beadlock wheels to be able to air down to low pressure on these tires? If so, do I need double beadlocks or will a single outside BL work? Is anyone running this type (46" tall by 15.5" wide military) of tire on a standard lip wheel without the beadlocks or even the "cold roll" edge that Stazworks talks about?

The bead on these tires are pretty big (tall and thick) compared to what I am used to (Jeep CJ type stuff).

Q3: Do the standard steel wheels you buy from Diamond Racing, Stockton, Longs Wheels work well or do I need to use something with a taller "lip" to cover the entire bead?

Q4: Is there an advantage to using a recentered HEMTT wheel versus a custom steel wheel? I have seen some nice Hutchinson Aluminum HEMTT wheels for sale and I hear (Pirate 4x4 threads) that they are easy to recenter. (Cost for the steel beadlocks are about $475 each)

Any assistance would be appreciated.

 

[M1075]

Don't go with the smaller lip wheels. Go with wheels designed to work with the tires. If you want to air down, go with double beadlocks. I ran some 395/8R20 on my jeep with 0 psi (valve cores pulled). You should be able to get recentered HEMTT wheels for about $300 each. New double beadlock inserts are $50 each.

 

[Barneyszoo]

I run 395s on A3 wheels, but you said you have a different bolt pattern. So I don't know whats out there with 8 lugs.

 

[Joaquin Suave]

The bead and sidewall on these tires seem very stiff. My truck is pretty heavy (9920 lbs) but these tires are designed for 9200 lbs or so at max capacity.

You do understand...That the load capacity of 9200 lbs is FOR EACH TIRE! In all honesty, they are WAAAAAAAAAAY more tire then you will ever need.

Have you looked at commercial off road tires??? Chances are you will be able to get a NICE bead-lock rim and NICE off-road tire for the cost of just getting a modified 20" military .

BTW: What is it???

 

[bdelaporte]

Thanks for the reply. Yes, I do know the rating is per each tire... Many run the military treads on vehicles much lighter than the 2.5 ton fair of my rig. In all actuality I did look at commercial tires, but they are not designed to run a CTIS as their sidewalls are way too thin for running at low pressure. I bought a set of NOS Goodyear MV/T for $500M00, you cannot beat the price. BTW, the truck is a Serbian Troop Carrier called a TAM. It is Deutz diesel powered and the only one in North America. It looks a bit like yours... Is it a Volvo?

 

[Joaquin Suave]

In all actuality I did look at commercial tires, but they are not designed to run a CTIS as their sidewalls are way too thin for running at low pressure.

What I meant was consumer off-road tires like BF Goodrich T/A's. They are designed to be deflated for rock-crawling and deep sand applications. I know there are several companies that make single and double bead lock rims and components. 9K lbs. is actually quite light, and certainly lighter than a F350.

The big issue (as I see it)...Is not overloading your drive line with massive rims and tires. I'd hate for you to have to learn Serbian, just it get replace some exotic obscure drive-line part.

My truck is a FMTV Prototype, her name is Libelula. If you do a search for libelula you'll see there is quite a bit written about her.

Good Luck!

 

[Flat Black]

with a truck that only weighs 10k pounds, you could run passenger car tires on there

If you are aired down at trail pressure on a large off road tire like a Super Swamper or Pro Comp or BFG, you are not going to be travelling fast enough to heat up the tires and do any damage to the sidewalls. If you are concerned about the weight rating (assuming you know your front to rear and side to side weight bias) just pick a tire like this (as an example only)

Iroks are available in 39.50x13.50R20 and are rated at 4100 at 65 psi (10 ply tread). That includes a safety margin of at least 5-10 percent, so those tires could hold about 18,000 pounds, plenty for your application.

Military tires and commercial truck tires rated at high pressures typically have thick sidewalls to support the high load ratings and are NOT designed to be aired down to trail pressure. This can actually damage the sidewalls or tire carcass. You may be able to go from 80 psi to 60 psi, or similar, but you cannot air a tire that is rated for load at 80 or 90 psi down to 10 psi on a heavy vehicle and have it live. On a three or four thousand pound rock buggy, sure this is not a problem, but it will ride like crap.

Off road tires like Iroks, BFG, etc are typically made to take low air pressures and also to be driven on the street to the trail. I would not want to daily drive a rig on 49" Iroks or 46" Baja Claws, but people do it every day.

Do your research and find out what tire is best for your application. You should also be able to get load and inflation tables telling you what the tire will take at a given pressure. If you think 20 psi is low enough for you and the tire will support your rig at that pressure then get a tire that meets those specs.

Additionally 20" wheels and tires are pretty common in the off roading world these days, so you should not have any problems finding wheels and tires to meet your needs.

.02

YMMV

 

[Joaquin Suave]

Military tires and commercial truck tires rated at high pressures typically have thick sidewalls to support the high load ratings and are NOT designed to be aired down to trail pressure.

That is not what Contential sayz about they're MPT 81's...

 

[seve7]

9K lbs. is actually quite light, and certainly lighter than a F350.

umm, 9k, is light when talking about vehicles rated over 2 tons or armored, but last i checked most 1 ton pickups were in the 7k range.

i dont think you really have to worry about overloading your drivetrain with those, as you 2.5 ton axles on your truck, its not insanely heavy, and it probably doesnt make all that much power. like the other guy said, your best bet is going to get some hemmt wheels recentered. the thing with off the shelf off road tires is that they are pretty weak, 9000lbs is going to be a lot for some of those tires, and they wont last nearly as long, and will have more puncture issues, the sidewalls on commercial tires are thick, really thick, so its really hard to have a sidewall puncture, and they have more tread depth than most off road tires as well.

 

[tennmogger]

I run 14.5 x 20 Michelin XL's on my U-1300 Unimog (German Military transport truck). These are on 20 x 11 wheels so a wider wheel is no problem. This is a 14,000 lb truck with the camper (little over 7000 front, a little under 7000 in rear). The XZL's are a similar radial tire carcass, just different tread.

I run them 40-45 lbs on the highway at up to 65-70 mph, with no over heating, and they wear slower and more evenly than if aired up close to maximum. The Michelin design plants the tread on the road for less squirm, less wear, and lets the flex happen in the sidewall. I have put enough miles on these tires to know this is optimum pressure for best wear (65,000 km in last two years, worn out 8 tires), and have made long distance tests from 35 to 65 psi. A test to me is like driving from Knoxville to Denver at one tire pressure setting and watching the results.

Max pressure rating is twice that, but load is half the rating. Load vs rating is approximately proportional.

I air them down to 20-25 psi for rock climbing and other offroad. Have never had a debead, yet, but I know other Unimog owners who have debeaded the same tire at 15 psi by rubbing a rock on the sidewall. That's about the lowest acceptable pressure IMHO. Sidewalls become very exposed at this low a pressure.

Other moggers have tried the IROK's, Swampers, etc and they work fine on the lighter trucks (404 Unimog, for example, 6000-8000 lb max), but wear out quickly. They are not made for a heavy truck.

The sidewalls are vulnerable on most any roadable tire used in the rocks, woods, or other hazardous locations. The Michelin X's work fairly well in sand, too. To me, there's no better all around tire, and the Military seems to think so too.

Bob

 

[gringeltaube]

..................... The XZL's are a similar radial tire carcass, just different tread.

Bob

Yes, if you are comparing the 365/80R20 XZL to the 14.5R20 XL, both being MPT. But the OP was talking about 395/85R20...!

Compare specs below....


G.

 

[tennmogger]

Thanks for pointing out the size difference!!! I thought we were talking about similar sized tires!

Bob

Yes, if you are comparing the 365/80R20 XZL to the 14.5R20 XL, both being MPT. But the OP was talking about 395/85R20...!

Compare specs below....

G.