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  1. #1
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    Avid BB7 Mechanicals-Am I Adjusting correctly?

    Okay, I just got these brakes and must say I like the feel at the lever and the power, but my first few rides on them were frustrating due to the front one rubbing almost constantly. I think I figured out how to adjust them, please let me know if this is correct:

    1. Loosen rotor bolts, squeeze and hold the lever in then tighten the bolts, alternating one bolt to the other. This will result in the rotor very close or touching the inboard pad.

    2. Back out the inboard pad one click at a time with the tool just until there is no rub or barely any rub (maybe just a little tinny sound of very light rub but wheel still moves freely when spun slow/no binding).

    3. Readjust the outboard pad to give correct feel at the lever.

    End result is that the rotor is much closer to the inboard pad - less daylight between rotor and inboard pad then rotor and outboard pad.
    Then going forward, should only need to adjust outboard pad for pad wear or possibly inboard pad a bit?

    Also, is some very light rubbing expected, and, why would they start rubbing again after adjustment?
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  2. #2
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    Quote Originally Posted by mtnbkrdr98
    Okay, I just got these brakes and must say I like the feel at the lever and the power, but my first few rides on them were frustrating due to the front one rubbing almost constantly. I think I figured out how to adjust them, please let me know if this is correct:
    I just followed the directions and they mounted up right the 1st time. No significant rubbing and great grab on the levers.
    GapRider MTB
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  3. #3
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    mtnbkrdr, I'm not sure if I'm missing some sarcasm or if this a serious question, but if this is really how you're going about setting up your BB7s, I'm cringing (well... I cringed anyway, then thought maybe this post is in jest?).

    Anyhow... don't mess with the rotor bolts, don't squeeze the levers, simply follow the instructions provided with the brakes.

    BTW, your step #3 is correct and should be used with both pads. The inside pad spacing affects the "on/off" feel of the brakes while the outside pad affects mainly the engagement point of the brake lever.
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  4. #4
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    Hopefully, it's a terminology mistake on the "rotor bolts". I think what he meant is the brake caliper bolts. On the BB7's, this is the correct initial setup method. Loosen the bolts holding the brake caliper slightly, squeeze the brake lever (I use a heavy rubber band on it to hold it down) and then tighten up the caliper bolts. This results in the brake caliper aligned in the same plane as the rotor. After you've done this, then yes, adjust inboard and outboard pads so there's the barest hint of daylight for each. The rotors may not be dead flat so you likely will get a little rub.

    Then, go do a few hard stops from speed to bed the pads and all should be good.

  5. #5
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    Sometimes you get unlucky

    I've installed a few sets of BB7s. Usually they go on easily enough, but last night I just finally finished an install-from-heck. Sometimes you just get unlucky.

    FWIW, your end result is where I like to end up. I like as small a gap as possible between rotor and inner pad.

    Is your rotor reasonably true? A slight warp in the rotor will often cause a rubbing sound each time the wheel spins. I know it sounds crazy, but I found it helpful last night to lightly clamp the brakes and turn the wheel while the pads were grabbing. That got rid of some very minor warpage. It was so minor that I could hardly see it, but it was enough to cause trouble.

    Make sure your caliper isn't moving slightly as you tighten the bolts. I had this problem big time with my front brake this weekend. Even though the pads were clamped to the rotor, the upper part of the caliper would move outwards slightly as I tightened down the bolts. A bit of finger pressure to hold the caliper in place helped a lot.

    Your basic approach sounds reasonable. I use a rubber-band to hold the brake lever, so that I can get down there and focus on making sure the caliper doesn't move as I'm tightening the bolts.

  6. #6
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    Yes, sorry, meant brake caliper bolts, thanks!

    Quote Originally Posted by feral
    Hopefully, it's a terminology mistake on the "rotor bolts". I think what he meant is the brake caliper bolts.
    There is a very slight warp in the front rotor so am getting very light rub in certain spots - it's somewhat annoying but probably not affecting anything

    thanks again
    Sound of Tires on Dirt - Sole Music; shared with friends - Soul Music.

  7. #7
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    Quote Originally Posted by mtnbkrdr98
    There is a very slight warp in the front rotor so am getting very light rub in certain spots - it's somewhat annoying but probably not affecting anything
    I get that sometimes. Spin the wheel in the stand, and it runs forever, but you get this regular rubbing sound every time the wheel goes around. It is annoying, isn't it?

    You could back your pads out a bit more, but back them out too far and you ruin the feel at the lever.

    Have you tried bending the rotor to straighten it? Are you familiar with doing that?

  8. #8
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    Squeezing the lever during installation is unnecessary and adds extra complication to the BB7 installation process. Avid describes this method in the BB5 installation instruction out of necessity -- the '5' only has one adjust knob.

    With the BB7, all that's required to align the caliper is to dial in both the inner and outer pads to where they're clamping the rotor, then tightening down the CPS bolts. This technique is outlined in Avid's installation instructions and video, and allows more precise, repeatable, one-handed control of this step.
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  9. #9
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    One thing I did with my BB7s was to dump the Avid rotors for some others. The Avid's weren't flat out of the box and that was really annoying. I put some Delta Aztecs on which were dead flat - problem solved. They've stayed that way, too.

  10. #10
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    Make sure your inboard pad is dialed out enough (away from the caliper) so that when you do all your tightening of caliper bolts (after you've dialed your outboard pad against the rotor--no squeezing of levers!) and you dial both pads back away from the rotor you still have plenty of clearance between the rotor and the caliper (in other words, there's plenty of inboard pad visible). If you don't have that clearance and you dial the inboard pad back some more on the trail, your rotor might bend over and scrape the caliper

    I've installed many BB7s and they don't always go on correctly the first time, for whatever reason. Sometimes it's just best to just start all over again---dial both pads all the way out, then dial the inboard pad in etc etc. Sometimes the pads don't go in or out of the caliper body like you thought they should be---dial one click, the pad must move, right? Sometimes not. Sometimes you have to squeeze the levers (after your caliper bolts have been re-tightened again) to correctly get the pads to get into position. Speedub.Nate is correct, no squeezing of levers is involved during caliper setup.

    And I don't go for absolute minimal pad/rotor clearance, like you necessarily have to have on hydros. Dialing a pad back to clear a slightly bent rotor is what I'll do, no prob.
    Last edited by xcguy; 06-01-2009 at 06:58 AM.
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  11. #11
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    Quote Originally Posted by Speedub.Nate
    With the BB7, all that's required to align the caliper is to dial in both the inner and outer pads to where they're clamping the rotor, then tightening down the CPS bolts. This technique is outlined in Avid's installation instructions and video, and allows more precise, repeatable, one-handed control of this step.
    Doh, you are correct .Nate. Forgot that you can do that with the 7's.

  12. #12
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    Thanks guys.
    i have more than you.
    ...because i have me and you.

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  13. #13
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    While it may not be necessary to squeeze the brake handle during setup, I don't think that it's "wrong" per se to do so. The end goal is the same: to get the pads clamped on the rotor so the caliper (hopefully) stays stationary and in alignment whilst one tights the mounting bolts.

  14. #14
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    Quote Originally Posted by JonathanGennick
    While it may not be necessary to squeeze the brake handle during setup, I don't think that it's "wrong" per se to do so. The end goal is the same: to get the pads clamped on the rotor so the caliper (hopefully) stays stationary and in alignment whilst one tights the mounting bolts.
    Don't be giving these guys wrong advice. You reach the end goal of aligning the caliper/pads with the rotor by dialing the pads to the rotor then tightening the caliper bolts. Squeezing the lever (as in, not setting the pads to the rotor by dialing them out) doesn't give a clue as to where the pads will be when you'd let loose of the levers. You'd then look down and start dialing pads all over again. Your rotor might be too far towards the inboard edge of the caliper but, hey, it's aligned. Just forget whether squeezing the levers during the process might work, it's the wrong way. These aren't hydros. With some squeezing the levers and telling their friends that's the way to do it, no wonder there's a certain percentage with BB7 setup "problems".
    A blind man searches in a dark room for a black hat that isn't there. Dashiell Hammett

  15. #15
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    Quote Originally Posted by xcguy
    Squeezing the lever (as in, not setting the pads to the rotor by dialing them out) doesn't give a clue as to where the pads will be when you'd let loose of the levers.
    I dial in the inner pad a few clicks tighter than where I really want it. That gives me room to back it out again to clear the rotor.

    Though at that point, I suppose I might just as well tighten the outer pad with the adjuster dial rather than clamping the brake handle.

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