When reading tyre sizes, you need to remember that the numbers mean -
17inch - wheel outer bead, or tyre inner diameter.
200 (mm) is the width.
60 or 55 or whatever it is, is the tyre height, as a percentage of the width of the tyre (aspect ratio).
So that not only does the change in aspect ratio affect the handling feel (side to side), it changes the gearing, and the amount of rubber in contact relative to the angle that the bike is tipped over!
On the rear, if you are an extreem leaner, then a taller aspect ratio helps over at extreem angles, because it will not try to hold the bike up, when well over and wanting to tip it further!
On the front, a lower aspect ratio speeds up steering, as it changes the line taken into the corner by steepening the steering angle, as it drops the front end, slightly, and it also changes the point of contact as the lean progresses.Taller tyres on the front will tend to scrub when subjected to acceleration into, and out of corners, as the drive pushes them wide. This scrubbing is more pronounced on longer wheelbase bikes.
Jacking, or dropping the suspension can help you get the correct settings to suit your style!
I have a perchant for earlier R1's, as I love the short wheelbase, and I have found that fitting a 190 section tyre on those models leaves little clearance for the chain, but just enough, if you run the standard 530 width 'O' ring chain and sprockets, given that my 98 R1 came from the factory with a 180 wide rear tyre.
Last edited by Rant; 01-17-2015 at 12:49 AM.