This past April, I purchased a 2009 K1300GT, and after putting 3500 miles on it, I found the back tire was wearing primarily on the left side, and was cupping as well. The service manager suggested a new tire. At that point in time, my bike had been at the dealership awaiting a left side switch assembly, as the left turn signal quit working. After checking the back tire on the loaner I had, which was also a K1300GT, with about 300 fewer miles on it than mine, I realized the rear tire was worn in an almost identical way: left side, and cupped. BMW, per the sales manager, claims "too many variables as regards tire wear" to replace the tire for me at their cost. Note, tire pressure maintained per specs, and no damage to my tire and same for the loaner. Both tires are factory installed Metzelers. Has anyone else had this problem? The dealership states they cannot tell if the swingarm is within specs or not. They think the problem is with the tire. By the way, my cruise didn't work when I picked up my bike and needs replacing and BMW states replace the right side also. I'm waiting for that switch at this time.