Not only are superbikes now using 200 and even 205 section tyres, more relevantly, supersports bikes are mainly running 190's now on 5.5" rims.

Quick question.
How does a motorcycle steer?

don't underestimate the side wall equation in all this.
now the big boys might be using larger tyres but they are not using 50 side walls.
I use a 190/55 some below are even on 60's