190/50ZR17R Tire

They've made the PR3 and are now making 3 versions of PR4 since the PR2. The PR4 is made in 170/60x17 in two if not all three versions. I have the PR3 in this size on my Trophy and LOVE it - way better than the PR2 was. The PR4 is reported to be better than the PR3, so that'll be my next tire.

If you put the 180/55x17 on your 5" wide wheel it will have a sharper crown than intended and may change your bike's handling traits a bit - maybe feeling a bit like falling over (or leaning quicker than expected) when turning. You'll need to be more careful until you find out how it handles for you. I have that size (Pilot Power 2CT) on my 1990 and it feels great, but I have the 5.5" wide wheel.

Cheers,
Glenn