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I just replaced the brake pads in my BB7 disc brakes for the first time.

I read up, watched videos, til I grasped what I was doing, and tried more than a handful of times. On the front brake, I can clearly see (with the wheel removed) that the pads are in a V position -- having a narrow gap further inside (the part harder to see), and a wider gap towards the outside. I assume this is just because of the way they sit around the spring.

The problem is, while the narrow part of that gap is (barely!) wide enough for the rotor, I can't get the rotor lined up in it properly. Even when the pads are dialed all the way out, and the caliper bolts are loose, it's hard to manually align it so there's no rub.

So, I tried all kinds of approaches, but in the end, here's something that doesn't seem right, and I can't figure out what's up:

1) Loosened caliper bolts 2) Turned pad dials all the way out 3) Turned outside pad dial all the way in (this was an experiment, I know it's not the right approach) 4) Turn inside pad dial til rotor is snug 5) Tighten both caliper bolts, a little at a time 6) Turn both pad dials all the way out

Even in this case, it was the outer pad that rubbed against the rotor and the inner one had a big enough gap. Again, I know that's not exactly the right approach, but after not getting the outer pad to pull back enough off the rotor, I tried this, and am not sure where to go from here, since the outer pad still won't back off enough.

5

If only one brake pad rubs and there is a gap between the rotor and the other pad, then your brake isn't centered well. To fix it:

  1. Use an allen key to loosen the caliper so that you can slide it around but it is still attached.
  2. Pull the brake lever. This way, the brake goes into a position centered around the disc.
  3. While still holding the lever, secure the brake again.
  4. Release the brake lever and find out that your brake doesn't rub any more!
  • 1
    The BB7 installation manual says to pump the lever five times then hold - I suspect usually the first time is enough but if things aren't quite as loose somehow the extra times might make an important difference. – Cascabel Jan 11 '16 at 2:02
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Lots of folks use Anderas' method and I'm sure it works for them, but it never did for me. What does for for me (it is similar)

  1. Loosen the caliper bolts, so the caliper will float around.
  2. Loosen the both adjuster knobs all the way, then tighten the inner one (the big red one) 3-5 clicks: depends on the bike. A Torx driver is handy for this.
  3. Tighten the outer adjuster all the way down (the small one).
  4. The wheel should not move at this point. Check for just a bit of clearance between the rotor and the caliper housing (not pad) on the inner side. If not, retry steps 2 and 3 with a different number of clicks. When ok, tighten the caliper bolts.
  5. Back off the inner adjuster 2 clicks and the outer 4.
  6. With a light source between the brake and you, observe the gap between the pads and the rotor. The outer gap should be twice the inner gap, and the inner gap should be small. If the gaps vary as the wheel spins, you may need to true your rotor.

Bonus tip: Wipe your rotors down with alcohol each ride, they will work well and will make (less) noise. BTW, I love my BB-7s: with a bit of knowledge and care, they are great brakes.

  • Right, this answer adds a lot of things specific to mechanical disc brakes. I don't have any experience with them. My answer is basically what works well with hydros; the question sounded exactly like that method should be applicable, too. – anderas Sep 23 '15 at 11:26
  • Thanks. I think your method works because most of the hydraulic brakes are self-centering and self-adjusting, and the BB7s aren't either. – jimbob Sep 26 '15 at 20:56
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I have experienced the same symptoms as you describe -outer pad angled, not returning fully, rubbing.

In my case, the issue appears to be dirt and/or corrosion in the caliper body. In particular, the pad retainer clips appear to be corroded, and this seems to cause friction at the top of the pad which the spring is not strong enough to overcome -the top edge of the pad therefore 'catches' as it slides back as the brake is released. Cleaning is first step. Lubrication may help, (grease, small amount, on retainer clip only DO NOT get any lubricant on pad or disc!!!). I plan to replace my corroded retainer clips with new, widely available as spares.

  • Gidday and welcome to SE Bicycles. Good first answer, please keep up the contributions. – Criggie Feb 16 '16 at 10:23
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Are your pads properly seated in the caliper? You should hear a snapping sound when the pad falls in the correct position. Sometimes this can be tricky with the BB7 and the pad may end up "floating", making the gap narrower than it should be.

When you are sure that pads are properly seated, center the caliper as per manufacturer's instructions.

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Some replacement pads don't allow the spring to fit properly. Lumps and bumps on the side of the friction material push the spring out wider than the metal backing causing it to catch on the caliper body preventing the pad from returning fully. Just clean up the side of the friction material until the spring fits within the width of the backing and it will return cleanly.

protected by Community Dec 20 '18 at 5:52

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