I put 15" R1R's on this spring, did have 13" with 888's. The outcome is superb, dry grip is the same as the 888's but in the wet they are unbelievable. I drove 400mls through France in pouring rain and was able to cruise along at 75-80 on the autoroute and that was with standing water, no way could I have done that with 888's. have now done 3k mls on them and the rears have only lost 0.5mm, these also come with 6.5mm new compared to 5mm with 888's - great tyre