Metzlers R value , my bro runs them & swears by em' ! I used em' on my GSXR 1100 of old, good rounded shape to the tyre, making for very adaptable/versatile lean angles in corners , I find the pilots like the old Michelin Hi-sport of the old days, real V angle to em' , your either straight up or in the corner at the lean angle dictated by the curvature of the tyre !