I just replaced a Goodyear tire that had flat spots in 5 different positions. We have only owned this motorhome about 4 months now, The previous owner had a blow out and had them put the goodyear on. I don't know if it was new or used when they put it on. It was mounted on the rear. Found it when I was putting two new Toyo on the front. It had not been balanced. I had the rest of the rear tires balanced. It felt like a front tire was not balanced, but I had just had them done 1500 miles ago. Thought one of the tires had thrown a weight. Rv now rides nice and smooth.