I just replaced my second this year. The first because something went wrong with the valve - won't hold air. The second because the tread started coming off. Age on both tires unknown, but multiple years for certain. I've done city riding, commuting, long-distance, goofing off, all on sewups, always with tire-savers, and with most tires lasting the life of the tread. Keep out of the trash along the side of the road, be especially vigilant if one rides 'bike paths' and tire life should be acceptable. Also, as pointed out, they are repairable.