I had mine balanced after purchase and one tire could not be balanced to within satisfactory specs and it eventually developed "cupping". The symptoms are: 38RL3 - flatware drawer fills up with "black powder" from the nickel rubbing off the flatware as it is being continually "jostled" in that center island from any out-of-balance tires. Sawdust from cabinetry joints rubbing together.
After replacing the offending 17.5" tire, all the above syptoms dissappeared.
