Yes I did search and did not find the info I wanted.

I know the SE180/60 tire will fit on the stock 17" rim on the dyna. My question is if I bought a 180/55-17, the 55 means it's a lower profile and would actually have a little more room under the fender, correct?

Just weighing my options for a new set of tires.

 

Most tire manufacturers recomend 5" wide wheels for there 180mm tires. The SE180mm Donlup has a 4.5" spec bead. Some have mounted other 180mm tires to there stock 4.5" wheel and I guess have done alright. I recomend talking to the tire manufacturer of the tire your interested in buying. Yes the 180/55 will fit but may not have correct shape on the 4.5" wheel.
Only other thing is the tire height and if is less then stock in height your speedo will read optimistic in speed.

 

Check out the Avon site. On their is says that they recommend a 180/55/17 for a 5.50-6.00 rim. I went with a 170/60/17 for that reason.

 

Ok. I'll take that advice gentlemen. Thank you.