I bought a very slightly used boat/trailer. 30 hours on the motor. I noticed that the tread (ribs) on the trailer tires seemed to be all different heights.....most wear being on outside tread. I figured the guy had towed the trailer (the little he towed it) with low air pressure. I have put the correct pressure in the tires and towed maybe a total of 400 miles. I now notice that on one tire the tread on the second rib from the outside is almost bald.......I'm wondering if this is an indication the wheels were never balanced and need to be? Thanks for any insight.