Here is what I know about this issue. I also wanted a wider tire and new rims. I measured, studied, measured, studied more and finally talked myself into fitting a 180 on the rear of my bobber. I went with a Metzler ME 880 (180/70/16) it was installed on a 16 x 5.5 rim. It fit and does not rub BUT there are a frw things that need to be considered. The Metzler 880 in that size measures about 175mm. This leaves me with a little more than an 1/8" of an inch between the tire and subframe. Not a whole lot .Now, you got options. If you go any wider you can adjust the preload on the shocks so tight that you get no suspension travel .this will prevent the tire from contacting the subframe but not advisable. Another option is go with a smaller diameter tire so there is no chance of the suspension traveling enough to make contact. As I said, mine fits but barely and I have no issues with anything touching. In my opinion anything wider than 175 mm is risky. I see no way a 200 will work. In fact if you're considering a 180 you need to research the tire you are going with. Some 180's are wider than 180mm. It all depends on the brand and model of tire.