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  1. #1
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    Avid bb7 brakes rubbing

    I just upgraded from v-brakes to some Avid BB7 mechanicals with 160 mm rotors. I installed the back brake and I just can't get it to stop rubbing. It seems like the adapter is too thick because the rotor is rubbing on it, not just the pad. I am totally lost on what to do. Is there some sort of thinner adapter or something? Or is it probably because I am totally inexperienced and installed it wrong?

  2. #2
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    avid bb7 have a pad adjust so first make sure that the pads are all the way out...next loosen the caliper from the adapter ( two allen bolts ).... spin your wheel and apply the brake while the caliper is loose...do not let go of the brake...while you have the brake applied tighten the caliper... now your caliper will be centered on the disc. sometimes the last step is easier if you have someone else pull the brake while you tighten... after the caliper is centered you can use the pad adjust to change how close the pads are to the disc..

  3. #3
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    Quote Originally Posted by Lovetheland
    I just upgraded from v-brakes to some Avid BB7 mechanicals with 160 mm rotors. I installed the back brake and I just can't get it to stop rubbing. It seems like the adapter is too thick because the rotor is rubbing on it, not just the pad. I am totally lost on what to do. Is there some sort of thinner adapter or something? Or is it probably because I am totally inexperienced and installed it wrong?
    If your rotor is rubbing the adpater then the IS mounts on the frame are too thick and need to be faced. This is not an uncommon problem with older frames with IS brake mounts, and is still seen on lower end new frames sometimes. In some cases if the particular model bike was not originally speced with disc brakes, manufacturers simply didn't face the mounts at the factory. Facing the tabs requires a rather expensive tool (to do it right) that isn't worth it to the average home mechanic, unless you really want one. So take the bike to your LBS with the brake, adapter etc. mounted so they can see the problem, and ask them to face the tabs for you. The facing process will remove excess paint and a little metal and ensure that the tabs are concentric to one another and parallel with the center line of the frame and hub. This should solve your problem.

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  4. #4
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    What a trip. I am having the same problem, but on a front brake with a 185mm rotor. I have set up BB7s before. I have them as my rear brakes. I understand (and like) how the setup works. But like the OP, my rotor is way too close to my mounting bracket. Mine doesn't rub, but it is very close. My problem is that there is not enough adjustment to keep the outboard pad from rubbing, much less to get the 1/3 - 2/3 spacing recommended in the setup.

    The forks are 2006 Rock Shox Recon 351, U-Turn. I was previously running some no-name mechanical brake, and it didn't seem to have this problem.

    Does it make any sense that these forks would have inaccurate mounts?

    I measured the width of both my old and new mounting brackets and the Avid ones are like .430 and my old cheapos were .400-.405.
    Straight is better than flat.

  5. #5
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    Quote Originally Posted by AchrisK
    What a trip. I am having the same problem, but on a front brake with a 185mm rotor. I have set up BB7s before. I have them as my rear brakes. I understand (and like) how the setup works. But like the OP, my rotor is way too close to my mounting bracket. Mine doesn't rub, but it is very close. My problem is that there is not enough adjustment to keep the outboard pad from rubbing, much less to get the 1/3 - 2/3 spacing recommended in the setup.

    The forks are 2006 Rock Shox Recon 351, U-Turn. I was previously running some no-name mechanical brake, and it didn't seem to have this problem.

    Does it make any sense that these forks would have inaccurate mounts?

    I measured the width of both my old and new mounting brackets and the Avid ones are like .430 and my old cheapos were .400-.405.
    1. The 1/3-2/3 thing is not needed if you watch the pad wear. Just center the caliper on the rotor.

    2. May need to remove some paint from the mounting tabs.

    3. Make sure the rotors are true
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  6. #6
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    ^Well, if I could center the rotor in the calipers, I would not be having this problem. Speaking from the point of view of being on or behind the bike: With the outside (left) brake pad dialed all the way away from the center (to the left), the rotor is already rubbing on the outside (left) pad, even with the brake caliper assembly pushed all the way to the left.

    I don't think the paint thickness is enough to make enough difference. The area is smooth on the fork tabs and on the mounting bracket.

    I was thinking about filling the mounting bracket down where it mounts to the fork tabs... maybe about the thickness of a rotor. The BB7 mounting alignment features would probably make up for any imperfections in my hand-filling.

    The rotor was a little bent/warped, and was rubbing on the mounting bracket in one area. I straightened it up a good amount, and it is pretty good now. I am gonna slap on a new rotor just for a sanity check.
    Straight is better than flat.

  7. #7
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    I am going to have the bracket machined down about .060 inch in the area where it mounts to the fork. I figure even if I screw it all up, I can buy a replacement bracket.
    Straight is better than flat.

  8. #8
    Rub it............
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    Please guys, follow Squashes suggestions. I've used every suggestion he has given for BB7's when I was running them. Never had a single issue.

  9. #9
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    I got no suggestion (not complaining). My situation is slightly different than the OP. I was hoping to hear from someone who knows stuff, whether the 2006 RS Recon is among forks which commonly have problems with excess thickness in the mounting tabs. But that didn't happen, so I decided to do effectively the same exact thing. With no additional information I decided it was safer to take the material off the cheaper bracket, than the expensive fork.
    Straight is better than flat.

  10. #10
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    So I modified the bracket and installed the brakes. Everything seems cool.



    Straight is better than flat.

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