I purchased a 2007 FXSTC, brand new. I have had a serious problem with the rear tire wearing out in the center in 1500 miles. I keep the air pressure exactly at the manufacturers suggested pressure of 42. as I have replaced 5 tires in 10,000 miles 3 of these at a tire pressure of 36, 38 and 40, the last two at 42psi. The dealer shakes his head, the tire manufacturer ( Metzler now on the last 4 tires says its the pressure that I have not kept it properly) I have had the tire rechecked to make sure its balanced properly and it has been, in fact at speeds up to 107 ( highest I've been) the bike runs very smooth. Anyone have a suggestion?