My opinion is this. S12 Rear And Dunlop 752 Front. I've tried the MS2 front, and it works great if you ride it hard (on it's side), but if you cunnyfoot it around it'll be a handful to control. Right now I have a Michelin MS2 on my bike, which I've modified to hopefully give a bit more traction in a straight line. I haven't tried it yet, but I have some national hare scramble this weekend to try it out on. Jon!