The TT owners and 5'er owners talk about the scrubbing one gets on turns on hard surfaces with non-steering tandem axles. Just thinking about the geometry of the tandem setup, one can understand why this would be the situation. The standard dual setup of course doesn't have this additional tire wear issue.
So far we've never had any issue with wedged rocks between the tires when RV'ing off-pavement with our standard single axle rear dual arrangement. This is probably more of a concern for the extreme off-road crowd than it is for a moderate off-pavement RV owner.
