I bought my 2011 FZ6R back in November with 1400 miles and I am pretty sure they are the stock tires, the tires are dated with 2011. Is there any specific life of a tire on when they should be changed? I was in a Military Sport Bike Rider course and one of the instructors said that usually by 4-5 years you should change your tire. The tires are not dry rotted or anything, but I am just use to car tires when the life is with tread and miles. Thanks.