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Old 12-12-06, 08:42 AM   #1
Ziemas
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Avid BB7 Disc Brake Only Works When Wet- Suggestions Please!

Here's a strange one. When conditions are dry my front Avid BB7 disc brake will not stop me. It's so bad that I can pull the leaver, push the bike and the front wheel will move a little. But when it's wet out and the brake is wet it works perfectly. I have new Avid pads and have cleaned the rotor. The brake is properly adjusted. The rear brake has no problems.

Do you have any idea what could be causing this and how I can solve it? Thanks.
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Old 12-12-06, 11:01 AM   #2
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The brake is properly adjusted.

Do you have any idea what could be causing this and how I can solve it? Thanks.
Are you sure the brake is properly aligned with the rotor? Avid gives instructions on its site on how to do this.

My front brake on my OCR-T was not working well when I got the bike - just like yours. I replaced the pads and aligned and adjusted the caliper. Now it works quite well. Don't forget to clean the rotor (alcohol or brake cleaner) when you replace the pads.
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Old 12-12-06, 11:15 AM   #3
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Are you sure the brake is properly aligned with the rotor? Avid gives instructions on its site on how to do this.

My front brake on my OCR-T was not working well when I got the bike - just like yours. I replaced the pads and aligned and adjusted the caliper. Now it works quite well. Don't forget to clean the rotor (alcohol or brake cleaner) when you replace the pads.
Yes, all is aligned and clean. It works beautifully when wet, terribly when dry.....
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Old 12-12-06, 12:14 PM   #4
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Is it a Road BB7 or MTB? Any funny sounds?

Mine seems to work about the same wet or dry...
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Old 12-12-06, 12:19 PM   #5
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MTB, no funny funny sounds.
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Old 12-12-06, 01:30 PM   #6
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My advice would be to go slow and avoid hills.
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Old 12-12-06, 01:30 PM   #7
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Or keep your water bottle handy to dash onto the rotor for a quick stop.
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Old 12-12-06, 01:32 PM   #8
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Seriously, if you've got it set up right, and new clean pads, what more is there?

You could: take off the caliper and make sure it's operating smoothly.
check the length of the cable and make sure there's no kinks or other bad stuff

Sorry, I can't think of what the problem could be...
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Old 12-12-06, 01:46 PM   #9
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How about this (if you have the time): clean both rotors first, wich alcohol. Then, swap the front and rear brake pads. If the calipers are really aligned properly, then the only thing could be some greasy substance in one (or both) front brakepads. Swapping front and rear pads, you could confirm this theory, because then the front would brake and the rear wourldn't. Perhaps even just a visual inspection of the brakepads could reveal something.
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Old 12-12-06, 02:30 PM   #10
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Originally Posted by wroomwroomoops
How about this (if you have the time): clean both rotors first, wich alcohol. Then, swap the front and rear brake pads. If the calipers are really aligned properly, then the only thing could be some greasy substance in one (or both) front brakepads. Swapping front and rear pads, you could confirm this theory, because then the front would brake and the rear wourldn't. Perhaps even just a visual inspection of the brakepads could reveal something.
Excellent idea! Thanks!
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Old 12-12-06, 03:04 PM   #11
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You could also swap rotors and (maybe ?) calipers, if needed...

When you take out your pads, check them carefully to see if they're unevenly worn (bad alignment).

And keep your water bottle full!
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