Several years ago I upgraded my Shorelandr' trailer to use radial tires; I bought some nice alloy wheels with tires mounted on them, load range E. Taking the machines (double trailer) to the lake I had a noticeable vibration and I could see the port side tire was bouncing significantly. Got to the lake, saw it had thrown its balancing weight (the stick-on kind). Took the wheel off, took it to a Firestone dealer, he balanced it and it passed but he had me come in and look at the tire whilst spinning on the machine. While the wheel was running perfectly true, there was still a noticeable movement in the way the tire ran, it just didn't run "true" in the side axis. Mechanic said, "I think this tire is not good", so I asked if he could put a new one on, he said his machine didn't/couldn't do 12" rims. So for now I think I'll put it back on the trailer and see how it acts, but I am leaning towards purchasing a 'better' tire in 145R12 size, but not sure I can find someone to mount it...
