I have a Dunlop Screaming Eagle tire on my rear solid Deuce style rim. It is a 180 60B17. My bike is a 2006 Dyna Street Bob with an upgraded rear wheel. The belt guards have been removed because of the tight tire clearance with the 180 tire. It measures 7 1/4" wide and comes within a half inch of the drive belt. I am having a lot of difficulty finding those exact same measurements in a new tire. I am able to find lots of tires with a 180 55/17 measurement. Will putting this different tire size make a difference? I expect that going from the 60 aspect ratio to the 55 would mean a shorter sidewall. Or could it mean the tire is wider? Any advice would be appreciated. Here's a shot of my tire from last year. It has now worn to almost bald in the centre 3 inches of the tread.