Just to note the part that failed on my single axle trailer was the pole tongue...not the axles or wheels/tires. I think that part of the problem was that I was towing with an "air ride" RV and it didn't follow the dips of the roads--the trailer did. There are some big bumps in Mississippi (where it failed) as well as in LA on I 10. A lot depends on the vehicle's suspension and wheel base as to how much it will affect ride.