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Scenario: New 525 disc brakes, koolstop pads. Avid fr7 levers.

Problem: the front works like a dream. The rear seems to pulse whn braking. it seems like it stops at 150% for about 30 degrees through the disc's rotation. I have realigned, alcoholed, re aligned, tried to burn through, everything i can think of and this is killing me! so much for modulation with this skid bandit setup.

please help me
 

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My bike was -TWO- Wheels!
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Mine do the same thing, except im using avids.

Got the 160 rear and if I use just the rear brake in stopping I can feel the pulsing. the rotor is perfectly true and the same thickness (measured with a micrometer)

Friend has the same setup with the same problem.
 

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summitlt said:
Mine do the same thing, except im using avids.

Got the 160 rear and if I use just the rear brake in stopping I can feel the pulsing. the rotor is perfectly true and the same thickness (measured with a micrometer)

Friend has the same setup with the same problem.
bummer... i have avid mech 160mm discs front and rear and have experienced pulsing since day 1 (or day 2 if you don't count the bed in procedure). I've tried truing the rotor, cleaning the pads and rotor, and realigning the caliper, but they don't seem to help. I talked to a service guy at an LBS and he said that pulsing was an inherent problem in all mechanical discs. I'm not sure how true that is... but it sucks if it is. I'm thinking about upgrading to hydraulics for better modulation anyhow.
 

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"El Whatever"
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burndtjamb said:
I talked to a service guy at an LBS and he said that pulsing was an inherent problem in all mechanical discs. I'm not sure how true that is... but it sucks if it is. I'm thinking about upgrading to hydraulics for better modulation anyhow.
Not true. Neither my Avid mechs or Shimano Deore mechs (BR-M515-LA) pulsed either front or rear.... look somewhere else.

Can be rotor thickness as Shiggy said. It can be some bed in problem. Have you checked your rotor for contamination, proper torque at the rotor, caliper mounting bolts, etc.???

BTW... input info is wrong... 525's are hydros. You mean 515's (normal or LA version)?
Newer Shimano brakes of this series have BIG note on the rotor which states "RESIN PADS ONLY".... Koolstops are semimetallic. That could affect your pulsing issues.

burnt.... if you want more modulation, just back the inner pad one or two clicks away from the rotor and maybe one click closer the outer one. Play a bit with your Avids before dropping cash on some hydros.
 
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