My original speedmaster front was past the wear bars in less than 3000 miles so I installed a set of K70's in 3.25 and 3.50-19. My K70 drive tire lasted about 3500 miles so I put the original Avon SM back on the drive and put another 8000 or so miles on it. It STILL has a good bit of tread left but I replaced it this spring with a Dunlop TT100 in 4.10-19. This tire seems to feel a bit "off" with the K70 front due to the different profiles, so I think I'm going to change out the front to something that will better match the TT100's design. I live in the hills of western PA and commute on both wet and dry roads. I drag my peg and brake pedal with some regularity and have only had that rear avon slip 2 times while stopping in the rain. The factory speedmaster front never felt good to me and I was happy to replace it.