Lefty: rotor rubs when hard turning- Mtbr.com
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  1. #1
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    Lefty: rotor rubs when hard turning

    When i lean in good i hear my front rotor rub just a hair. Is this normal on a new bike? I figure the wheel will flex but not tbe hub. Or the fork is flexing.

  2. #2
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    Normal. They will wear in.
    and no, I am not missing the other half of my fork....

  3. #3
    Helmetless Crasher
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    Not normal.

    What is it rubbing? Pad? Adjust the caliper alignment and/or "bite point".

    Or is the rotor rubbing metal? May have the wrong caliper bracket bolts (too long).
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  4. #4
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    Just sounds like the rotor rubbing a pad. Just seems of with all the talk of how stiff the lefty is.

  5. #5
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    check caliper position,
    there is no flex in lefty, and even if it was, it won't produce any rubbing.

  6. #6
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    Yeah, I never had any rotor/pad rub w/ my lefty - ever. However, the shop used the wrong (too long) bolts and the rotor rubbed the bolts, which were less than .5mm from the rotor. There are Lefty-specific caliper bracket bolts one should use.

    I'd check caliper alignment.
    I'd check the bracket bolts - they should not protrude through the bracket on the rotor side.
    Then I'd check the trq on the axle bolt - set to spec, don't over trq.

    My rear rotor/pad rubs all the time and I'm constantly adjusting it. A QR is way more flexy than a Lefty axle.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  7. #7
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    Looks like the pads are not coming back as far as they did when it was new. Mabye a 100 miles on it but it flew back on a plane with me and i have heard the factory bleeds are not the greatest.

    Its not a hard rub. I just hear the ting of a rub. Very very light. I will also check the wheel. Bolts are not comong through the bracket

  8. #8
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    that "ting" you describe sounds like the bracket bolts hitting rotor.

    Are your bolts shiny stainless? They should be.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  9. #9
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    Yes shiny. And they dont go out the back of the bracket.

  10. #10
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    I hink I have this narrowed down. This only happens on pavment. It seems the sring that spreads the pads away from the rotor has a bit of looseness to it. I think its just vibration from riding on the side lugs of the tire causing the pad to resonate on the rotor.

  11. #11
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    my guess is it is wheel flex, make sure your spoke tension is up to par. Depending on what wheel build you have you may not be able to make this noise go away completely.

  12. #12
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    A flexing wheel shouldnt effect the the disc. Its mounted to the hub. The hub flexing should be the only thing that causes the rotor to move.

  13. #13
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    I had this problem, and after multiple checks of wheel being trued, hub inspected, new brake pads/bleed, the mechanic finally realized the pistons had shifted, both were shifted to the right. So on hard turns, the rotor was contacting the piston itself when the wheel flexed (which all wheels/hubs do to some degree). After re-aligning the pistons, problem solved.

  14. #14
    Uncle
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    Couldn't hurt to double check the torque on the rotor bolts too, and check for rotor trueness.

  15. #15
    Genius
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    Quote Originally Posted by Entrenador View Post
    ..... and check for rotor trueness.
    Yup. An easy check would be to rotate the front rotor to the back.
    "I think im gonna go to walmart and look at the mountain bikes and see if i can salvage the rear frame."- Nick_Knipp 3/21/12

  16. #16
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    Checked the bolts front and rear, they are all good. Rotor is straight. It only happens on pavment. Its just the pads are a bit to close and rolling the tires at cetain speeds is causing the pads to vibrate and hit the rotor.

  17. #17
    LA CHÈVRE
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    What brakes are you using?

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  18. #18
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    Oem elixr 3.

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