I have got this like new Trek 4300 recently. I noticed if you hold the front brakes tightly and try to move the bike forward and backward, there is a little bit of play. It seems like the rotor holds firm but the rim moves a little bit. I removed the front tire and checked the rotor but it appears to be firmly attached to the center with no play. I would say the rim moves about 5mm each way( at the tire end) is this normal?