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  1. #1
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    juicy 5 calipers drag on rotor

    Hey everyone,

    Just got a new stumpy comp and I was noticing that the front calipers seem too 'tight' and drag on the rotor at all times. When you lift the front of the bike to spin the front wheel the wheel only spins about 4-5 times before stopping. You can see that the calipers are making contact at all times. How can I open them a little bit to fix this? Thanks.

  2. #2
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    +1 i have the exact same scenario. please advise someone

  3. #3
    neutiquam erro
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    Is it a constant drag? Just trying to eliminate out-of-true rotor as the culprit...

    If it's a more-or-less constant drag then proceed as follows...

    First, check to make sure the wheel is "sitting" properly/securely in the dropouts, and that the QR skewer is tightly secured. I do this by leaning my chest & weight on the handlebars (or ditto on the seat for the back) as I reach to tighten the QRs.

    Next logical guess would be that it was a bad CPS (caliper positioning system) initial set-up.

    Loosen the CPS bolts (the 2 bolts that attach the caliper to the adapter - they are the ones with the stack of washer-lookin' dudes) just a few turns so that you can wiggle you caliper a little bit.

    Grab you lever and squeeze 5-6 times, and then squeeze hard & hold (or use a rubber band to hold it down), This will "center" the caliper & pad grip onto the rotor. Tighten the CPS bolts down to snug (so caliper can't move), and then release the lever. Spin the wheel and check for drag. Repeat as necessary until no drag. When there is no drag, tighten the CPS bolts to specified torque. Any better?

    Some folks slide a business card in between each pad and the rotor when they do this CPS set-up. Not required, but may help too. Certainly doesn't hurt.

    Cheers, Chris
    Last edited by Chris130; 06-16-2007 at 09:07 PM.
    [SIZE=2]Now is the time on Sprockets when we hammer.[/SIZE]
    [SIZE=1]'05 Blur Classic (1x9) || '06 SIR9 (SS) || '06 Brompton P6L[/SIZE]

  4. #4
    Daniel the Dog
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    The most likely problem is....

    Quote Originally Posted by zeppman
    Hey everyone,

    Just got a new stumpy comp and I was noticing that the front calipers seem too 'tight' and drag on the rotor at all times. When you lift the front of the bike to spin the front wheel the wheel only spins about 4-5 times before stopping. You can see that the calipers are making contact at all times. How can I open them a little bit to fix this? Thanks.
    The pistons need to be reset by pushing on them with something that will not break them. Be careful. I usually use an old pair of pads because resetting the pistons with a screwdriver on the pads usually mucks them up unless you are very careful. Some people use a closed ended wrench to reset the pistons.

    The second issue could be a system that is slightly overfilled not allowing the pistons to retract all the way. Opening up the bleed and pushing the pistons back a smidge can let some fluid out.

    Last, do you have straight rotors? Bent rotors can cause grief. I can usually strighten them by hand.

    There is my two cents. I typically get a bit of rub after changing pads but it goes away quickly. Also, take it back to the LBS and have them work on them if it is a new bike, if you are stuck.

    Jaybo

  5. #5
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    Quote Originally Posted by Chris130
    Is it a constant drag? Just trying to eliminate out-of-true rotor as the culprit...

    If it's a more-or-less constant drag then proceed as follows...

    First, check to make sure the wheel is "sitting" properly/securely in the dropouts, and that the QR skewer is tightly secured. I do this by leaning my chest & weight on the handlebars (or ditto on the seat for the back) as I reach to tighten the QRs.

    Next logical guess would be that it was a bad CPS (caliper positioning system) initial set-up.

    Loosen the CPS bolts (the 2 bolts that attach the caliper to the adapter - they are the ones with the stack of washer-lookin' dudes) just a few turns so that you can wiggle you caliper a little bit.

    Grab you lever and squeeze 5-6 times, and then squeeze hard & hold (or use a rubber band to hold it down), This will "center" the caliper & pad grip onto the rotor. Tighten the CPS bolts down to snug (so caliper can't move), and then release the lever. Spin the wheel and check for drag. Repeat as necessary until no drag. When there is no drag, tighten the CPS bolts to specified torque. Any better?

    Some folks slide a business card in between each pad and the rotor when they do this CPS set-up. Not required, but may help too. Certainly doesn't hurt.

    Cheers, Chris
    I use this procedure on my bike relatively often as I have to take my wheel off to put the bike on the back of the car... The caliper just needs re-seating and then is fine again. This works every time for me!
    2013 Cannondale F29 2
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    2009 Cannondale Rize 4

  6. #6
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    Hey guys,

    thanks for all the replies. I think it was the pistons. I very cautiously pushed the pads apart with a flathead, and now there is only a very slight drag on the rotor by one pad. I know they need to be re-aligned now, but I don't want to do it since i don't have a torque wrench. Next time I'm by the bike shop, I'll take it in and have them do it. Thanks!

  7. #7
    banned
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    What? You think the bike shop is going to use a torque wrench?


  8. #8
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    Really? I thought they would. I'm just afraid to damage something since I don't know what 90 in. lb. (or whatever the specified torque is) feels like...

  9. #9
    neutiquam erro
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    On those CPS bolts, "snug & a tug" with a non-torque wrench will work fine for ya. Not worth a trip to the LBS simply to torque that in particular.

    Cheers, Chris
    [SIZE=2]Now is the time on Sprockets when we hammer.[/SIZE]
    [SIZE=1]'05 Blur Classic (1x9) || '06 SIR9 (SS) || '06 Brompton P6L[/SIZE]

  10. #10
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    When you tighten to CPS bolts, make sure you go back and forth between the two. If you completely lock one side in while the other side is still lose, you will likely mess up the alignement, even though the pads are tight agains the rotor.
    "Early bird gets the worm", but the second mouse gets the cheese...

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