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  1. #1
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    BB7 caliper alignment

    Having trouble aligning the caliper, question is do I start with both pad adjustment knobs completely backed out? they do not specify, I do have the CPS bolts backed out slightly.The inboard pad knob is a booger to turn barrel adjusters ARE adjusted correctly so as not advance the torque. been using BB7s for four years on my other bike and am now just having a closer look at proper adjustment.

  2. #2
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    seems the inboard caliper adjust knob is the problem..really had to turn alot harder to engage it more than 10 clicks.....think its defective, seem to have the proper ratio of rotor clearance...after 2 freakin hours!

  3. #3
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    This actually depends a little bit on how worn your pads are, but in theory, it doesn't matter.

    The important thing is that the caliper doesn't inadvertently deflect the rotor while performing this task, which can happen if your frame's tabs are slightly out of spec relative to the rotor, OR if you're just not being careful.

    With lots of material left on pads, I like to start by backing both pads out. I then turn the outboard (moving) pad IN about 7 clicks, and try to make the face of this pad my "reference plane," i.e. the face with which my rotor should align.

    Why 7 clicks? Because this is how many clicks back I like my outboard pad (as counted from the "fully clamped" position), for my preferred engagement point when I squeeze the lever. If you like a quicker engagement, then you can do fewer clicks.

    At this point, it should be obvious if you have enough side-to-side play in your caliper. On some of my bikes, I'm required to use simple hardware store washers or even 3mm shims as spacers, to move the adapter bracket further away from the frame or fork's mounting tab.

    At that point I can crank in the inboard (fixed) pad. If you've got the newest BB7s, you can use an allen wrench to turn this difficult adjustment knob.

    Because you've verified that you have sufficient side-to-side caliper play, and have set the face of the outboard pad to the face of the rotor, the inboard pad should do nothing to deflect the rotor. You should just be clamping the caliper in the position dictated by the rotor.

    I mentioned pad wear only because the pads could be worn to the point that, fully backed out, their surfaces could both be hiding "inside" the caliper. Seven clicks may not be enough to cause the outboard pad to clear the caliper body enough to touch the rotor. Likewise, you may be attempting to shift the caliper over so close to the outboard pad that the face of a worn inboard pad can't get close enough to the inside face of the rotor. You'll have to either modify this technique to ensure both pads are making contact, or install new pads.

    Edit: Forgot to note that this whole alignment centers around rotor flex to the inboard during use. Avid recommends only 2-3 clicks of clearance in their instructions. I find this to be way too grabby. I prefer the inboard (fixed) pad to be around 5-7 clicks out for smooth, progressive engagement -- a little grabbier for the front, a little weaker for the rear. Whatever your preference, this ensures the rotor won't contact the caliper body.
    Last edited by Speedub.Nate; 01-09-2008 at 06:46 PM.
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  4. #4
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    I just set up my new BB7:
    - CPS loose
    - inboard +23 clicks
    - outboard to squeeze the rotor
    - tighten the CPS
    - adjust inboard slightly out not to rub
    - adjust outboard to suit the lever play

  5. #5
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    thanks guys..helps alot, I think I have a defective unit, the inboard rear knob goes ten click that are not very distinct then it it very difficult to turn the knob further with out pain, my thumb is raw, there is no visible allen fitting on my 2007 or maybe I am lame,I intend on returning it.Your info make sense and I am able to get proper engagement now, they are brand new.7 clicks makes more sense than 0 or halfway (27) their online advice and included instructions are very vague. how many clicks on the inboard ? about 20 I think.

  6. #6
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    Quote Originally Posted by thomasmore1535
    how many clicks on the inboard ? about 20 I think.
    I don't know, I don't count at that point. Just dial the inboard in until the caliper is clamping the rotor tightly, then secure the two CPS bolts to ~80 in lb.
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  7. #7
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    Quote Originally Posted by Speedub.Nate
    I don't know, I don't count at that point. Just dial the inboard in until the caliper is clamping the rotor tightly, then secure the two CPS bolts to ~80 in lb.
    Ok! the lightbulb finally went on! this advice makes it clear to me..thanks so much

  8. #8
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    I have the new 08 BB7s and the inboard adjustment is very hard to turn.

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  10. #10
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    This is better compared to info supplied with brakes, I used it on 2 sets, all worked.
    From : http://www.parktool.com/repair/readhowto.asp?id=124

    The procedure for AvidŽ mechanical caliper pad alignment is as follows:

    If the caliper is attached to a bracket, check that the bracket is fully secured to the frame or fork.
    Loosen caliper-mounting bolts so caliper is loose on bracket. Caliper adjustment is made at caliper to bracket interface, not at bracket to frame/fork interface.
    Loosen brake wire pinch bolt if it is secured.
    Check that both pad adjusting knob dials are turned fully counter-clockwise to move pads fully away from rotor.
    Turn the inner pad adjusting knob clockwise approximately 1 turn (about 24 "clicks').
    Turn the outer pad adjusting knob clockwise until pad fully secures rotor. This aligns pads and caliper body to rotor.
    Snug each caliper mounting bolt. Then alternatively tighten first one bolt, and then the other until both are fully secure.
    Draw slack from the brake wire and secure pinch bolt. Do not allow caliper arm to move upward when drawing slack from brake.
    Set pad clearance. Inner pad (fixed pad) should have twice the gap to the rotor as the outer pad (moving pad). Loosen fixed (inner) pad adjusting knob 2-3 clicks counter-clockwise. Loosen moving pad adjusting knob 4-6 clicks counter-clockwise.
    Squeeze lever to test caliper brake. Adjust lever modulation setting by moving pads inward or outward from rotor by using both pad adjusting knobs

  11. #11
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    I should have thought to look at the park tool sight, was not aware of it...thanks! my thumb is still raw though.

  12. #12
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    I am returning the rear brake....inboard dial is defective, very difficult to turn.

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