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  1. #1
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    discs rubbing brakes

    For some time on my front wheel the disc rubs the brake pad at one point in its rotation. If it rubbed throughout the rotation, this would be a non-issue, but it seems to be affecting braking (braking is not as constant). Assuming the rotor was warped I replaced it and the brake pads, to no effect. Shouldn't the hub be aligned regardless of whether the wheel is perfectly true? I doubt I have truing issues anyway as I have not been riding that hard and use some pretty good wheels. What should I try next?

    I'm using Avid BB7s with Mavic Crossmax XLs

  2. #2
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    Quote Originally Posted by 310ScottK
    For some time on my front wheel the disc rubs the brake pad at one point in its rotation. If it rubbed throughout the rotation, this would be a non-issue, but it seems to be affecting braking (braking is not as constant). Assuming the rotor was warped I replaced it and the brake pads, to no effect.
    If it's really as you say, clean the mount surface on the hub. Eyeball the rotor and see where where and how much it's off.

    Quote Originally Posted by 310ScottK
    Shouldn't the hub be aligned regardless of whether the wheel is perfectly true?
    Correct. That is the undisputed advantage discs have over rim brakes.

  3. #3
    cougarbait
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    it sounds a lot like the rotor is warped... also just in case, check rotor bolts for proper tightness. like vk45de mentioned, spin the wheel and look into the caliper to see which part of the rotor is rubbing, take a adjustable wrench, and true it.
    09AS-Rsl/09Six

  4. #4
    Owner, Spoke Apparel
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    My guess is that your caliper is out of alignment. Get down at eye level, watch the rotor as it spins through. Is there equal space on the left and right side of the rotor? If not, your caliper needs to be realigned. This is easy to do. PM me if you need a step-by-step. And yes, even a true rotor can rub only at one point if the caliper is not properly aligned.
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  5. #5
    cougarbait
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    Quote Originally Posted by meneone
    And yes, even a true rotor can rub only at one point if the caliper is not properly aligned.
    care to explain this to me??
    09AS-Rsl/09Six

  6. #6
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    You've never had this happen to you? Dunno what to say.....I've seen this happen quite often.
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  7. #7
    cougarbait
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    Quote Originally Posted by meneone
    You've never had this happen to you? Dunno what to say.....I've seen this happen quite often.
    I don't think it's physically possible for the rotor to rub at only one point if it is true.
    09AS-Rsl/09Six

  8. #8
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    I understand. In theory it makes no sense. I've been working on cars and bikes for a long time. The solutions to many mechanical challenges are often overlooked becuase we use reason and logic as opposed to just trying what may seem simple and unnecessary. All he needs to do is check to see if the caliper is centered. Takes two seconds and is part of standard brake care and maintenance....
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  9. #9
    ~Disc~Golf~
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    Quote Originally Posted by Lambdamaster
    I don't think it's physically possible for the rotor to rub at only one point if it is true.
    it's not
    Honestly... ahh I give up

  10. #10
    cougarbait
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    if his caliper was misaligned, and his rotor was true, then it would be rubbing continuously. The rotor is the only moving part when the wheel is spun, so how could it rub at one point if it is true??
    09AS-Rsl/09Six

  11. #11
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    What if the caliper was misaligned for a while and the pad unevenly wore...then the caliper shifted again? You can't rule this stuff out guys. That's all I'll say about it.

    PS - great signature quote, highdelll
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  12. #12
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    I'm sure you guys have confused him with all this mechanical theory, hell reading this thread required more thought than I've put into anything all day -- and im still confused. I could add my advice but that would just interupt the flow of confusion. Im off to get another beer and reread.

  13. #13
    cougarbait
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    Quote Originally Posted by meneone
    What if the caliper was misaligned for a while and the pad unevenly wore...then the caliper shifted again? You can't rule this stuff out guys. That's all I'll say about it.

    PS - great signature quote, highdelll
    then it would rub continuously, provided the rotor was true
    09AS-Rsl/09Six

  14. #14
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    Maybe the hub is not running true? If a replacement rotor is having the same problem, this is where I'd look.

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