I have not had issues with 225-70-19.5 lrG tires on my mdt. I would agree with grit dog, get into to 50 or lower on some time sizes. Locally some cement rigs are using 35-40 series ties in the front axle. This have 6-8" of sidewall too. No issues from what I've heard or seen.
The real issue IMHO with LOW profile tires will be the actual sidewall height per say. Have 2", you will have issues. Have 5-6+", you have sidewall height to allow flex and not hit the rim. I would also assume, higher psi in a given tire size, would also not allow the sidewall to flex, such that the rim hits a curb, pothole etc to damage it.
As I stated before, plus and minus's to the two tire sizes I mentioned above, add in an 18-20" rim equals, 265mm in width, same 31.5" overall diam. Just lower sidwall% height, those could have a higher potential for rim damage, be it on the street, or off roading.
Marty
