Don't know about the hugger clearance to be honest, I found this link for you... http://www.sportrider.com/five-percent-difference and I read this on a Yam forum which you might find useful .... Originally Posted by blacknzr1 i was reading of a guy with a 07 r1 who claims a 190/55 rear tyre gave him a lot more grip over his stock 190/50 rear tyre. im not sure what to make of that statement, weather its true or not... has anybody else done this?? what do you think?? MY .02: The 190/50 is going to have the same CONTACT patch as the 190/55. The grip part is going to come the tyre compound itself! The 190/55 is a taller tyre than the 190/50, this just allows you to turn in quicker. Will you benifit from a 190/55, yes. It is cost effective for the street? Depends on your taste. Most likely you or your buddy won't use the potential of a 190/55 vice a 190/50 on the street anyway. As for your buddy having more grip because of the tyre size - not so much as the compound. Also running a taller tyre will change your geometry - so look at resetting your suspension.
Taller tyres have a larger contact patch at lean, also tip in better, hence a lot of rear slicks are a larger profile
I can only share my experience. When I switched to a 55 profile, the bike just felt much more nimble and a bit more planted on lean. I was well happy with my choice to switch.
Maxxis Diamond 190 55 I have done 6k miles already and will use for another 2k. Much difference comparing to size 50 and I can get them for £139 pair. No need to buy dunlops bridgestones or pirelli.