I have been looking very seriously into getting new tires on my bus here is what I have found:
The local school districts will retread the tires (11R22.5 are the current size) once and after that exchange them to the tire company.
My bus has 20" Widowmaker style bud rims, NOBODY will put tires on these anymore. I've called everywhere.
New 20" split rims are no longer made, at least that is what everyone is telling me. So a new set would have to come from the junkyard.
Replacement tires for the 8.25-20 are around $160 each mounted and balanced.
I can fit on some new 22.5" wheels which will run me $145.57 each new. Maybe I can find some cheaper at a junkyard.
However new tires for the 22.5" wheels which are 11R225 are an incredible $270 mounted and balanced.
Uhg, I don't think my bus is going far till someone wrecks their truck.