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  1. #1
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    2009 XT brakes are so loud that they make children cry... checklist of things to try?

    I have a 2009 Giant Anthem X2 with M775 brakes and a Fox f100. I run the metal Shimano pads and the stock 160mm rotors. Early in this bike's life the brake noise problems began. Over the last year the howling has reached comic proportions. People can probably hear me a mile away and I must be disturbing animal migrations or something. Thing's I've tried:

    -Replacing pads. (Well, the old ones were worn and the new ones squeal just as much.)
    -Aligning the rotor/caliper. (I've tried this several times front and back many times with no change in the noise.
    -Cleaning the caliper/frame contact points.
    -Bleeding the brakes (attempting to improve power.

    Things to note:

    -Both brakes squeal like a mofo.
    -My fork and suspension linkage and headset are play-free but the stock WTB hubs on this bike are poorly constructed. The bearings came with play in them and even when the bearings are replaced, there is still play! Awesome.... Could the vibration of the brakes be amplified by the "rattly" hubs? When braking I can actually feel vibration from the rear of the bike.
    -It rained hard while I was out riding today and when the rotors got wet the noise subsided temporarily. (The brakes also didn't work so well and you would expect.)
    -The front brake isn't terribly strong, and I wish it was.

    Thanks for your tips.

  2. #2
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    A few things to look at here as I have run the 775 brakes on 3 different bikes with no sound related issues.

    1. Toss the metallic pads. The only real benefit with metallic pads is longer life, but resin/organic pads have better modulation and braking power. Only other reason I would run metallic pads is if you are doing really long sustained descents, in which you should be running larger rotors anyways.

    2. Are you running the Shimano rotors? Most other brands tend to be louder and have less than optimal contact alignment with the pads.

    3. Not sure how you are aligning the calipers, but I always put a light oil lubricant on the caliper mounting conact points and spin the wheel applying light lever force to stop the wheel and tighten caliper bolts incrementaly to correct torque spec. Better to be a little too tight than loose.

    4. If you are a big guy (210+ lbs.) you should be runnning a little larger rotor unless this is a dedicated XC race bike. Larger rotors offer a very small weight penalty in relation to better brake temp management.

    5. One other rotor related possibility is that they are mounted in the wrong direction. Sounds stupid, but they are directional and from time to time, even the builder mounts these things in the wrong orientation. If you don't see a directional arrow facing outward from the center of the wheel towards you, then they need to be flipped.

    Good luck...Brake sound related issues are a pain to recover from and they drive me nuts as well. This is why I always prefer to run Shimano brake gear...

  3. #3
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    Thanks!

    -I've heard organic pads are quieter as well. The only issue is, don't they die quickly in wet conditions? I live in the PNWet.

    -I have stock 160mm shimano rotors which are facing the correct direction. I weigh 176lbs but do a lot of long and fast descents and should probably have 180mm rotors. For what it's worth, they squeal immediately on any sized hill.

    Should I be greasing the mounting area on the fork/frame?

  4. #4
    ronbo613
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    -I've heard organic pads are quieter as well. The only issue is, don't they die quickly in wet conditions? I live in the PNWet.
    I live in the Columbia Gorge and have XT 775 brakes. I only use organic or resin pads. Metallic,or sintered pads always squeal, I don't care how long they last.

    -I have stock 160mm shimano rotors which are facing the correct direction.
    I run a 180 in front and 160 in the rear. I ran 180s front and rear for awhile but the rear tire skidded too much. I weigh about 190 and my rides are all up and down.

    the stock WTB hubs on this bike are poorly constructed
    My Giant Trance X came with WTB hubs. They blow. Always loose, especially the rear. I don't think that's the main cause of your problems. Try organic pads(I use Alligators)

  5. #5
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    Quote Originally Posted by dromond View Post
    Thanks!

    -I've heard organic pads are quieter as well. The only issue is, don't they die quickly in wet conditions? I live in the PNWet.

    Should I be greasing the mounting area on the fork/frame?
    I have never heard of quicker wear in wet conditions, but have no personal experience with that. For what its worth, on my 6" bike I run 203 rotors front and back, ride about 300-400 miles per month and brakes last about 6 months.

    I put a very small amount of lubricant on the top and bottom of the caliper mounting points (slotted hole faces) only so that when I start to apply torque to the mounting bolts, the calipers don't tend to shift from one side to the other.

    I also have much more success tightening the calipers in very small increments, spinning and slowly stopping the wheel every time I increase bolt torque. Most procedures just tell you to apply brakes on a static wheel and incremently tighten bolts...
    Last edited by ebnash; 09-25-2011 at 10:43 PM.

  6. #6
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    Quote Originally Posted by ronbo613 View Post
    I live in the Columbia Gorge and have XT 775 brakes. I only use organic or resin pads. Metallic,or sintered pads always squeal, I don't care how long they last.

    I run a 180 in front and 160 in the rear. I ran 180s front and rear for awhile but the rear tire skidded too much. I weigh about 190 and my rides are all up and down.


    My Giant Trance X came with WTB hubs. They blow. Always loose, especially the rear. I don't think that's the main cause of your problems. Try organic pads(I use Alligators)
    Yes, I should switch to a 180 in the front. As it is I wail on that 160 pretty hard. It's good to hear that I'm not crazy regarding the WTB hubs. They are light, and I want them to be good... but they just suck. The freehub even failed on me mid-ride once.

    Quote Originally Posted by ebnash View Post
    I have never heard of quicker wear in wet conditions, but have no personal experience with that. For what itsl worth, on my 6" bike I run 203 rotors from and back, ride about 300-400 miles per month and brakes last about 6 months.

    I put a very small amount of lubricant on the top and bottom of the caliper mounting points (slotted hole faces) only so that when I start to apply torque to the mounting bolts, the calipers don't tend to shift from one side to the other.

    I also have much more success tightening the calipers in very small increments, spinning and slowly stopping the wheel every time I increase bolt torque. Most procedures just tell you to apply brakes on a static wheel and incremently tighten bolts...
    That's pretty much how I align them but I'll try again with a little lubricant. Cheers

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