On May 13, 2013, at 10:20 PM, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:

Even though a "55" series this is still a fairly tall tire size. If you hit a large enough tire or some other obstacle something has to give. Tire, rim or some other suspension part. 

I'm not sure what those sentences mean, but do know, from experience, heading W into Durango in a very heavy rain, running over some rocks that were washed into the
road from the heavy monsoon, that both R tires/rims were blistered and bent. Had to have that taken care of when I got into Durango, and when I got home, immediatedly
got 70 series tires (Michelin also). I've been using sidewall aspect ratios of anywhere from 65 to 75 since that 55 Durango experience, in similar to identical conditions,
and have never had any problems with blistered/blown sidewalls, or bent rims. I don't tend to drive fast enough on dirt roads, especially rough, rocky roads, to have
ever done any damage to my tires or rims. I think speed plays a role in this, and low aspect ratio tires don't seem to fare as well in my experience.

Bob