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Old 03-11-09, 11:59 AM   #1
epnnf
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mech disc brakes don't work so good

2008 C'dale Bad Boy, w/4500 miles; original brake pads. I keep the pads clean & adjusted, and I think the cable is finished stretching. Problem is, they're just not effective. I gotta use 3 fingers on each lever; squeeze like crazy; only slows me down, not really 'stops'. When new, they were great. Ideas?
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Old 03-11-09, 12:06 PM   #2
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New pads. Once they get dirty with oil or grease, they can't be cleaned effectively. Rotors can be cleaned.
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Old 03-12-09, 07:46 AM   #3
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did the performance drop off suddenly, or was it gradual?
either way, check the rotor width. i suspect after 4500 miles they might need replacing as well.
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Old 03-12-09, 09:13 AM   #4
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If you clean the rotors too much then you are working against yourself. After 4500 miles new pads are in order. You won't believe how your power goes back up with new pads (might as well put new cables on too). Check to see if you need new rotors at this point as well. Clean the rotors once very good when you replace the pads then do not touch them after that.
The rotors need to bed in with the new pads - if you keep cleaning them after that they will have less power until the pads rub the surface up again.
I am sure their is a scientific explanation for this about the rotors being filled at a microscopic level with some of the brake pad material that helps in braking but I am not 100% sure.
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Old 03-12-09, 01:33 PM   #5
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thx 4 advice
I'm gonna put new pads on, see how that works. The rotor seems ok, but I don't have a professional eye; how often do they need to be replaced?
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Old 03-12-09, 01:52 PM   #6
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looks to see if it is worn - there will be a ridge where the metal had been rubbed thin by the brake pads- the rotor arms will be thicker than the actual braking part of the rotor
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Old 03-12-09, 01:53 PM   #7
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Mechanical Avid BB7s on my cross bike...works terrific! I'm not sure what the problem is with yours, though I suspect some of the above suggestions may be getting close.
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Old 03-12-09, 10:58 PM   #8
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Are you using the front or rear brake? Try maximum braking test with rear-only first, then front-only.
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Old 03-13-09, 05:06 AM   #9
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Just helped a friend last night with a similar case. He had BB-5s. After pulling the pads from my son's bike and trying them on my friend's bike, we came away convinced that he needed new pads. We cleaned his rotors, swapped in my son's pads as a test, and it was like a miracle occurred.
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