Hydraulic Disc Brakes

GarrardRJ Posts: 11
edited April 2012 in The workshop
Recently i have purchased a Trek Sportster 10 which is a fantastic commuter bike together with the sporster mudguards made especially for these bikes. This is my first experience of disc brakes and have found them excellent Elixir 3 's . Now my question is this . When i apply the front brake it looks as if the wheel pulls to the left (the side the disc/caliper is on ) by about 7/8 mm. This i have only noticed recently as i was applying the brake quite hard going down hill. The front suspension obviously compressing a bit. Now it looks like the wheel is really loose but everything is fine. I can see the wheel/tyre move due to looking down at the mudguard/tyre line. Is it just what happens ? Is it one of the things that happen as the suspension compresses (it is the first bike i have had with front suspension) or could the wheel be mounted too far to the right on the fork ?
Any advice welcome


  • estampida
    estampida Posts: 1,008
    no no no

    So there should be slight (almost un-noticeable drift to the left when braking) but no that is not right, check every thing is tight, and the go to the lbs, as the fork could be goosed.

    is it a welded steel fork (a mate had a giant dj bike with an OEM steel fork and it was total crap)

    but the wheel should not move around 8mm on braking, could just be a crap qr, or something else
  • pdw
    pdw Posts: 315
    No - it absolutely should not do this. First thing to check is the QR. Disc brakes put a lot of force downwards on the axle, and if the QR is not done up properly, or is poor quality, it can slide in the fork. Definitely get it checked, as you really don't want the front wheel coming out.
  • shouldbeinbed
    shouldbeinbed Posts: 2,660
    get it checked that's not right. Assuming the wheel is properly aligned and secured tight in the fork - not simply staying in place because of your weight on the bike and the lawyers lips stopping it falling off when unweighted.

    If you turn the bike upside down hold the wheel and jiggle it, does it move to any significant degree and if so where from? if it is at the wheel hub it could be the cones allied to a poorly aligned/unevenly compressing brake caliper, if the whole wheel and forks moves together it is more likely to be faulty forks or badly assembled.
  • GarrardRJ
    GarrardRJ Posts: 11
    Well took the wheel out and checked everything and found nothing amiss. Will try it out again when riding but doesn't do it when do weight over the fork and/or no person on the bike. I am sure its an optical illusion but will look at going to my local bike shop for them to have a quick look. Thanks for the replies :)