Need to know if I can put a 160mm or 180mm rear tire on my springer without changing or modifing frame or swing arm?

160 probably, 180 is pushing it- doubtfull

Why the change? I find that unless you go to a really wide tire, with a wide tire kit and a bunch of money, that there is not much noticable difference.

Many Thanks, MadDog. That was about what I needed to hear. OR see. Didn't think it would make much difference.

I think you would end up being unsatisfied. Like the supplement commercials... "adds up to 25%" well 25% of 2 inches won't get ya in the show LOL

I am toting more weight now and I wanted the stability of a wider tire, but if I am gonna spend that kind of coin, I will get a new fat boy. .lol