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  1. #1
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    New Avid pads too thick?

    I just replaced the pads on my rear Avid Juicy 7, with Avid brand organic pads. The problem is, there's virtually no room between them for the rotor. After a lot of tweaking, it's at the point where there's perhaps a few MICRONS of clearance on either side, although when you squeeze the lever it feels like there's none at all. I made sure the pistons were pushed in as far as they would go, and the pads definitely did click into place. I went to two different bike stores, and both said it's just a matter of letting the pads wear in. Even with the old pads, I had problems with that same brake rubbing, to the point where one LBS actually machined down the rotor to make it fit. Has anyone had the same experience? Anything I can do to increase the clearance?

  2. #2
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    You say that the pistons are retracted "as far as they would go". Does this mean that they won't go all the way in, so that the back of the pad sits flush with the caliper?

    When was the system last bled? Who did it?
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  3. #3
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    I don't agree with the letting the pads wear in advice. You just have to let a little fluid out of the system. Loosen the clamp and rotate the lever till it's level. Slowly open the fill cap/screw on top. Gently push pistons back and excess fluid will drip out. Just because the pistons are back as far as they will go doesn't mean there isn't too much fluid in the system. This worked for me on J-5's.

  4. #4
    meh....
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    Quote Originally Posted by Zothecula
    Even with the old pads, I had problems with that same brake rubbing, to the point where one LBS actually machined down the rotor to make it fit. Has anyone had the same experience? Anything I can do to increase the clearance?
    Did anyone ever think to really look into caliper issues, too much fluid, etc., before machining down the rotor? WTF? What kind of a bike shop would machine down a brake rotor?

  5. #5
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    "What kind of a bike shop would machine down a brake rotor?"

    I think you might be surprised...
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  6. #6
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    Quote Originally Posted by SteveUK
    "What kind of a bike shop would machine down a brake rotor?"

    I think you might be surprised...
    What kind of bike shop has the proper tools to turn down a rotor?

    Anyway, what could you gain, a 1/100 of an inch?

    The zoth has some weird issue here, either a bad caliper or overfilled reservior.
    You better just go ahead and drop that seatpost down to the reflector... the trail gets pretty rough down there.

  7. #7
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    "What kind of bike shop has the proper tools to turn down a rotor?"

    How should I know? And did anyone mention that the shop used the proper tools?

    "Anyway, what could you gain, a 1/100 of an inch?"

    Depends how much was 'machined', I suppose?

    My point, which you've missed by some distance, is that it's not unusual for shops to try all kinds of odd 'fixes' without considering/attempting the (possibly) obvious.
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  8. #8
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    I'm pretty sure the backs of the pads are flush up against the calipers, they "clicked" into place and are lying quite flat. I'll double-check, though, and perhaps let some brake fluid out. Thanks, guys!

  9. #9
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    "I'm pretty sure the backs of the pads are flush up against the calipers, they "clicked" into place and are lying quite flat."

    OK, I was just making sure that the system hasn't been over-filled. If it had, the pistons wouldn't be able to retract fully into the caliper and so there would be a gap between the caliper and the back of the pads. By the way, the pads will click regardless of piston position, so that isn't confirming that they are fully retracted.

    I bleed certainly isn't going to do any harm, especially if the system has two year-old fluid in it. Normal recommendation is between one and four years (vague, I know!!), depending on use. I like to change mine every year, regardless, although I do quite a lot of descent riding. To be honest, you should generally bleed the system as one of your first checks when experiencing problems with rubbing pads or brake noise.

    Back to the problem at hand; if the pads are right back against the caliper and yet they still won't allow enough room to allow the rotor to run through, then as far as I can figure there must be a manufacturing/casting fault with the caliper. You could have the pads sanded down, but other than that I don't see any scope for finding space. I find this possibility a little unlikely, given the manufacturing process (as I understand it), and would explore all alignment checks first, starting with having your brake spots faced.

    With respect to your current shop, I think you could do worse than to pop into a different shop and let them take a look at your brake. It's always easier to determine faults when the brake is to hand.
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  10. #10
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    Quote Originally Posted by Cobretti
    You just have to let a little fluid out of the system. Loosen the clamp and rotate the lever till it's level. Slowly open the fill cap/screw on top. Gently push pistons back and excess fluid will drip out. Just because the pistons are back as far as they will go doesn't mean there isn't too much fluid in the system. This worked for me on J-5's.
    I 2nd this. I had to do the same thing on my J5s last year when I changed the pads.
    Warning: may contain sarcasm and/or crap made up in an attempt to feel important.

  11. #11
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    Quote Originally Posted by SteveUK
    "What kind of bike shop has the proper tools to turn down a rotor?"

    How should I know? And did anyone mention that the shop used the proper tools?

    "Anyway, what could you gain, a 1/100 of an inch?"

    Depends how much was 'machined', I suppose?

    My point, which you've missed by some distance, is that it's not unusual for shops to try all kinds of odd 'fixes' without considering/attempting the (possibly) obvious.
    GOTCHA
    You better just go ahead and drop that seatpost down to the reflector... the trail gets pretty rough down there.

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