The reason i asked is because i had a wee off on boxing day and noticed that the front tyre had a couple of cuts in the tyre wall,where the bike hit the crash barrier support, as i had the TKCs put on a few weeks before and kept the michelins to put back on in the drier weather, I changed the damaged TKC for a michelin I already have, but do i need to put the michelin on the back aswell or will the knobbly be ok on the back?