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  1. #1
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    Centering the disk between the pads

    Yesterday had a great fun of bike experience that included some quite exhaustive uphill climbs, fast down rides and few quite nasty (for my so far not very experienced opinion) singles with rocky downhills, led to two crashes.. (now wearing long-sleeved short to work in spite of sweaty hot sun - just to hide quite badly scratches arms - not to shock people at work...)

    Upon my arrival home, inspecting the bike I noticed the front wheel is lose laterally - the quick release was opened. Just wondering when it has happened and how long did I drive with lose wheel...
    No problem to tighten it back, however now have the disk non-centered in the caliper (between the pads). It rubs noticeably against the right pad (inner). I was trying to center it by releasing the wheel to allow lateral movement again and tightening it up attempting to keep the disk in the middle if between-pads spacing, not unsuccessfully.
    I inserted a business card between the disk surface and the right pad, squeezing the brake and holding and re-tightening the wheel. Then, once the brake is released, pulling out the card I see the disk gets back touching the pad and rubbing against it.

    I inspected the disk visually for any mechanical impact (should it needs straightening) - it seems straight.

    Is there any proven way to do that other then bringing the bike to the shop for that ?

  2. #2
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    loosen up the caliper and center it. you have to remember to tighten the QR the exact same amount each time or this will happen every time.

  3. #3
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    There's a solution to tightening the QR the same way every time.

    http://www.1upusa.com/quicknuts.html
    My Bike: '03 Specialized HardRock FrankenBike
    My Blog: http://http://kona0197.wordpress.com/

  4. #4
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    Quote Originally Posted by micro224
    loosen up the caliper and center it. you have to remember to tighten the QR the exact same amount each time or this will happen every time.
    Either that is BS, or I happen to tighten my QR the exact same every time without thinking about it.
    -elake

    "I don't half-a$$ anything, for me it's whole-a$$ or nothing."
    -elake

  5. #5
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    Quote Originally Posted by Kona0197
    There's a solution to tightening the QR the same way every time.

    http://www.1upusa.com/quicknuts.html
    or a clix skewer

  6. #6
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    Quote Originally Posted by elake
    Either that is BS, or I happen to tighten my QR the exact same every time without thinking about it.
    I guess you're just that good because it's fairly common knowledge that that's an issue.

  7. #7
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    Quote Originally Posted by alexzabr
    Yesterday had a great fun of bike experience that included some quite exhaustive uphill climbs, fast down rides and few quite nasty (for my so far not very experienced opinion) singles with rocky downhills, led to two crashes.. (now wearing long-sleeved short to work in spite of sweaty hot sun - just to hide quite badly scratches arms - not to shock people at work...)

    Upon my arrival home, inspecting the bike I noticed the front wheel is lose laterally - the quick release was opened. Just wondering when it has happened and how long did I drive with lose wheel...
    No problem to tighten it back, however now have the disk non-centered in the caliper (between the pads). It rubs noticeably against the right pad (inner). I was trying to center it by releasing the wheel to allow lateral movement again and tightening it up attempting to keep the disk in the middle if between-pads spacing, not unsuccessfully.
    I inserted a business card between the disk surface and the right pad, squeezing the brake and holding and re-tightening the wheel. Then, once the brake is released, pulling out the card I see the disk gets back touching the pad and rubbing against it.

    I inspected the disk visually for any mechanical impact (should it needs straightening) - it seems straight.

    Is there any proven way to do that other then bringing the bike to the shop for that ?
    Firstly the safety issue...

    I had a QR open up on me on a rocky downhill, no prob got off and did it up...

    Then I checked it all over and did it up properly for sure....

    Next ride it opened up again...thank god for lawyer lips....anyway I got a new QR and it has never happened again...


    Second, I center the pad in the caliper...if the pads rub I just lever them back all the way with a knife and then reextend them...

    If that doesn't work I have a sticky piston that I clean up and then it works.

  8. #8
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    Quote Originally Posted by micro224
    I guess you're just that good because it's fairly common knowledge that that's an issue.
    After a certain amount of clamping pressure the only thing that is going to happen is the skewer is going to be in tension and go into the elastic deformation zone. The hub frame interface (caliper-rotor alignment) is not going to be affected by this. If the hub goes into elastic deformation (from compression) it still will not affect the caliper-rotor alignment. If the frame goes into elastic deformation (from compression), again, still no affect on caliper-rotor alignment.

    So maybe you could say, you have to tighten your skewer a certain amount, and above that, alignment will be fine.

    It used to be 'fairly common knowledge' that the world was flat. Doesn't mean it was right.
    -elake

    "I don't half-a$$ anything, for me it's whole-a$$ or nothing."
    -elake

  9. #9
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    Well, thank you all, some great solutions to learn from...
    I just managed to solve the centering issue following the "playing card" approach...worked quite straightforward, almost no fiddling...

    Every day I learn a new lesson in bike maintenance...

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