I would really like to step it up to a 190 rear tire on my S4Rt. I like the idea of having more contact with the ground. I know it's possible on a 5.5" rim but thinking it may be a better idea to go with a 190/55 as the profile of the tire should be closer to the 180/55 BT16's. Anyone have a preference? I hope I'm not opening a can of worms starting a tire thread. STG has a great deal on all things Michelin http://stores.sportbiketrackgear.com/Categories.bok?category=Michelin+Tire+Detail (http://stores.sportbiketrackgear.com/Categories.bok?category=Michelin+Tire+Detail)
In my experience, a 190/55 is TOO wide for a 5.5" wheel. If you have to have a 190, get a 190/50. 190/55's are generally used on 6" wheels...
A 190 will not really give you more contact patch, in fact just the opposite usually happens. A 5.5 rim squeezes the beads together more then they are intended to be and causes the tread to push out. You end up riding on a taller arc and the bike will feel like it is "falling" into hard turns. To illustrate this, think of holding a balloon with a hand on each side. Push your hands together and see what happens to the outer circumference.
IIRC, a 180 is the widest your can go with a 5.5
Like said above, you will get nothing out of a 190 on a 5.5 rim other than a few less dollars in your wallet. I've run several of them because a 180 was not available at the local bike shop at the time I needed a new rear tire.
An exercise in futility .... maybe?
LA
Ducati put a 190 tire on a 5.5" rim on some SBKs...
Don't remember if they were 50 or 55s.