The 606 was mounted a month ago before the Kenda. The problem only started after mounting just the Kenda a couple weeks ago. I'm pretty sure it is just a defective tire and I'm going out in a few minutes to check for it being out of round. It may settle down after some more break'in. ps. I just got finished checking it and it appears to run between 1/16th and 3/32nds out of round. As I posed before not enough to get rid of the tire. just break it in more, and use it for light trail/offroad.