Mon Oct 22, 2018 4:47 pm by cornbinder89
Ok, lots of stuff to get to here.
1st, rim width matters! Your truck presently sits on 9.00xx20's IIRC. That means they are on 7" width rims or less. A 10X 22.5 tire on a 7.5 width rim would be the tubeless equivalent of the 9.00x 20. They would be the same height diameter and width as the tires you have now, and if the same load rating (ply rateing) they will carry the same load.
Your comparison of the Accuride and Maxon rims was flawed because you were comparing different width rims. The wider the rim the more weight it is designed for. An 8.25" 22.5 are designed for around 7400 lbs, a 9" 22.5 can carry 9000 or if a high cap 9" is spec'd 10,000 Lbs. A 7.5" 22.5 is designed for less because the tires that fit it are lighter cap also.
You can't jump rim width willy-nilly. you must check that there is enough room so the wider rim and tire will not hit the frame or springs on the inside and body on the outside. On the front the tie rod and brake hose must clear and the also there is clearance when the wheel is turned lock to lock.
You can be reasonably sure that a 10x 22.5 tire and wheel can replace the 9.00x 20's you have now, if fitted on 7.5" width rims. When switching from tube to tubeless, you go up one tire size and one step in rim width and add 2.5" to the rim diameter.
Those 20"tires are made for Military rims that bolt together with an O ring to seal the joint, or can be fitted with a tube. Either way you are looking at special rims . Since they are for single mounting only, a special rim made for the rear with two bevels are required and a special front rim with the offset to place the center of the rim over the center of the hub. Look at Accurides "Super Single" rim for spoke wheels to see what I'm talking about. So you need different rims for front and back if running super wide tires on spoke hubs. I've never seen spoke rims for those wide base 20" tires, the military favored disk type wheels.
There is a difference (many actually) in the design of tubeless and tube type rims. Tubeless have the rim end very near the bead and the bead angle is 15deg. Tube type rims, the side of the rim extends further up the tire to support the tire and the bead angle is 5 deg. This means that both tubeless and tube type rims end at aprox the same point. If you are planning to run low pressures for sand, you will be less likely to loose a tire with tube type.
Normally, as long as the tires have at least 20 Psi you would be safe in re-inflating without worry. BUT in your case, you have no idea as to the condition of the rims, they could be rusted to the point they are too thin to hold the tire contained. You really should pull the tires off the rims, clean inspect and paint the inside, then you'll know they are good to use. Jack the axle up, remove the valve cores and take the rims off, then dis assemble. Unlike tubeless rims, which will tend not to seal air long before they rust to the point of being weak, Tubes will hold air on the rim that has rusted paper thin. So Until you know the condition inside, assume they are degraded. They don't have to be rust free and shiny inside, but you want to remove all flaky rust, and paint, while inspecting to see that the metal is thick. You want the tire to be able to slide on the rim, not be stuck on a band of rust. If the bead can slide to the seat, the lock ring will be seated and locked in.
Tube type tires that have sat on the rims for a long time, especially if low on air, tend to form a rust band inside the tire where the tire, flap and rim meet. This can make them very hard to break down. I have been lucky and had tires that have been on for 40 years, break easily and ones that have been on much less time be almost impossible to get off. It all come down to how much moisture has been able to get in to the assembly.
As to flats with tube type rims, I've had 2 steer tires let go at 70 Mph and one at 55 and found them much easier to deal with then tubeless, no "gutter" in the center of the rim to cause the tire to flop back and forth like a tubeless rim has. I have had both tubeless and tube type flats, both with heavy loaded steer axles 12,000 + Lbs.
You are not going to "overcome" the 7.17 ratio with tire size. Either re-ratio (if possible) or add an Aux trans between the main and transfer case.
The spokes on the rear (how wide the flat portion of the spoke is) and the spacer band will determine how wide a tire/rim combo can be placed on the hub, but the truck spring and frame may not allow the widest combo the hub will allow. Both truck and hub must be taken into account.