Heavy Truck Tires

[charlieaarons]

Before you go to the r20s, do you plan South America? R20s are unavailable in South America. Strange but true. A 365 or 395 22.5 is a better choice for 99% of your driving.

I don’t believe those sizes exist in 22.5. There’s 385/65R22.5 (common worldwide), and 425&445/65R22.5, much less common.
And then there’s the issue of beadlock availability, for preventing debeading at low pressure.
I’m not aware of any beadlock availability for xy.5 tires and wheels (2 piece wheels are necessary for internal beadlocks) with the unusual exception of 2 piece Humvee 16.5”.
Lots of people don’t think they’ll ever need to deflate their tires to prevent getting stuck (or to get unstuck). Until they do. Debeading is a fairly gruesome and effective way to ruin your day.

 

[Joe917]

I don’t believe those sizes exist in 22.5. There’s 385/65R22.5 (common worldwide), and 425&445/65R22.5, much less common.
And then there’s the issue of beadlock availability, for preventing debeading at low pressure.
I’m not aware of any beadlock availability for xy.5 tires and wheels (2 piece wheels are necessary for internal beadlocks) with the unusual exception of 2 piece Humvee 16.5”.
Lots of people don’t think they’ll ever need to deflate their tires to prevent getting stuck (or to get unstuck). Until they do. Debeading is a fairly gruesome and effective way to ruin your day.

I regularly aired down to 70psi for comfort and 40 psi for soft stuff with the 315 22.5 80. That tire is too narrow. Sure you're not going to go down to 10 psi with it!

 

[Iain_U1250]

Thank you. I don't have those kinds of wheels. I need to find a video on how to change a spare that doesn't have a rim on to the rim of the damaged tire. I also need a good list of what tools I need to make this spare change out in the field.

I made a video on how I swapped my tyres on normal wheels and the two piece wheels.
You will need a proper bead breaker and tyre irons, not the little ones for car tyres. I got the proper Michellin set of three, they are great. I use Tyrepliers to break the bead on the tyres.

As far as 20" wheel vs 22.5" wheel go for off- road trucks.
These are the normal 20" rim contour - they make sure the tyre stays on the bead at lower pressures.


This is the 22.5" wheel rim conour, much lower, makes it a lot easier to get tyres on and off, but you need to keep the tyres at a higher pressure or they will de-bead and ruin your day.

 

[mog]

Sample of 20 and 22.5 rim profiles

 

[Blowby]

Some great information here, and thanks for sharing it in a manner I can understand.
We are running 385/65R22.5,s and I am in the process of getting a deflation system setup so that we can be a little more comfortable off-road, so this being said would you guys advise not to go below 40 psi for this particular tyre.
Thanks Roger

 

[Joe917]

It's not just the airing down, it's how you drive. Straight you're pretty safe but hard turns or off camber and you could be in trouble. The tire manufacturer will have a table with weight, tire pressure and max speed.

 

[MiwatoMikoto]

I ran into a similar issue on a road trip last year and found help through mobile truck tire repair Montreal - they came out fast, swapped a blown tire on my rig in the middle of nowhere, and had me rolling again. Saved me from having to tow it into a shop. If you're around that area, it's worth keeping their contact handy just in case.

 

[gator70]

When you select a rig platform under 16000lbs, you save yourself all theses troubles. A rig above 16000lbs is not necessary for a expedition rig.

 

[Neil]

When you select a rig platform under 16000lbs, you save yourself all theses troubles. A rig above 16000lbs is not necessary for a expedition rig.

In your opinion.

You could say that a vehicle no bigger than a Land Cruiser " is not neccesary ". But it might be what people want.

Everyone's circumstances and desires are different .

Neil

 

[yamaha225]

In your opinion.

You could say that a vehicle no bigger than a Land Cruiser " is not neccesary ". But it might be what people want.

Everyone's circumstances and desires are different .

Neil

Exactly, saying that over 16,000 isn’t necessary is like saying we don’t really need to transport goods around the country with semi trucks. We could really do just fine if we shipped everything in pickup trucks.

I for one have a F-350 as my expedition rig to be, but if I could afford a bigger rig you better believe I’d have one. Are there unique things to consider with a bigger rig? Sure, but they’re damn cool, really comfortable I’m sure, and capable.

Awesome rig OP, looking forward to the build!

 

[gator70]

Exactly, saying that over 16,000 isn’t necessary is like saying we don’t really need to transport goods around the country with semi trucks. We could really do just fine if we shipped everything in pickup trucks.

I for one have a F-350 as my expedition rig to be, but if I could afford a bigger rig you better believe I’d have one. Are there unique things to consider with a bigger rig? Sure, but they’re damn cool, really comfortable I’m sure, and capable.

Awesome rig OP, looking forward to the build!

My rig is a commercial truck 4x4, the composite habitat (spec at 19'x8'x8') built out completely, sleeps 4, weights 4000lbs dry. I don’t see anywhere close to weight requirements exceeding 16,000lbs.

 

[sprocket3]

When you select a rig platform under 16000lbs, you save yourself all theses troubles. A rig above 16000lbs is not necessary for a expedition rig.

In the first page of your build post you talk about having to upgrade to heavier axles. Can clarify why you'd want lower weight rig that needs heavier axles?

My thought was to buy a heavy rig and stay well under the max rating. This chassis is rated to 40,000lbs.

Isuzu npr 4wd

I start my project with this as the end goal.

forum.expeditionportal.com

" I have fabricators, and we use f550 axles."

The Ford F-550 Gross Vehicle Weight Rating (GVWR) typically ranges from 17,500 to 19,500 pounds.

 

[charlieaarons]

It looks like tilting the cab to get at the engine might be…interesting.

 

[mog]

It looks like tilting the cab to get at the engine might be…interesting.

Fuso and Isuzu DOKA cabs don't tilt for maintenance (single cabs do)

 

[gator70]

In the first page of your build post you talk about having to upgrade to heavier axles. Can clarify why you'd want lower weight rig that needs heavier axles?

My thought was to buy a heavy rig and stay well under the max rating. This chassis is rated to 40,000lbs.

Isuzu npr 4wd

I start my project with this as the end goal.

forum.expeditionportal.com

" I have fabricators, and we use f550 axles."

The Ford F-550 Gross Vehicle Weight Rating (GVWR) typically ranges from 17,500 to 19,500 pounds.

Yea, read the rest - Not correct

My rig is converted at RidgeRock

Sits on 4000lb 12 ply tires

The real issue here is about correct weight planning and to avoid military tires by choosing a platform with weight categories over 20000lbs

I can't image needing a special order tire shipment costing $1000 while on the road to Alaska. In one YouTube video the guy was in LA, CA and ordered tires that took 5 weeks to arrive.