My first 29er , Scott Scale 950 , bought last week , when I sit on the bike and apply both brakes , I can rock the bike backwards and forwards , they are Shimano centre lock . I have looked this up and it's a common problem , the shop I bought it off , thinks it's not a problem really . I think it is because at the end of the day you should have no movement , I know from the very first time you brake the rotation will all be in the right direction so you should not feel this . Do you all think this is or is not a warranty issue as eventually the splines could wear etc etc etc .