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  1. #1
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    Rotor hole buzzing.

    This more of an annoyance than any function problem.

    Is there any way to get rid of this buzz from the rotor holes. It happens at higher speeds, of course.

    I happens on both the front and back brakes. The mount tabs are properly faced.

    It was there a little with my Magura Martas when I had the SL Drilled rotors on there. I then switched to the wavey SL rotors and it was not there.

    With my Formula K18's it seems to be a little more annoying. Probably because the Oro rotors and R1 rotors I used have more holes.

    I know its the holes because the sound changes when I change the rotor.

    This also happens with 3 different types of pads, organic, sintered, and swissstop (whatever they are)

    I was thinking beveling the "first contact" side of the pad
    Or, cut a thin channel in the pad material.

    Anyone come across an easy solution?
    Lead by my Lefty............... right down the trail, no brakes.

  2. #2
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    I used a carbide bit & drill press & cut a radius in all my holes (both sides). Or rather they now all have a lager hole & taper in at the center to the original size. Actually shaved off just under 30 grams from each rotor & made them much quieter under hard breaking. The rotors are Hayes 203mm & running Stroker Ace brakes. It takes away a bit of contact area but I haven't noticed any change in stopping power whatsoever. Of course they already have quite a bit of contact area anyway with the larger Ace pads.

  3. #3
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    Never heard of that before? How fast do you have to go to get that from the rotors? I once hit 80km a hour on my bike, but don't remember any buzzing. Of course I may of been too scared to notice anything.
    Friends don't let friends cheer for the TML

  4. #4
    No, that's not phonetic
    Reputation: tscheezy's Avatar
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    The issue is probably this: when the rotor hole enters the pads, it carries with it the air inside the hole. The rotor and pads are warmer than the air entrained in the hole, so the air expands and sort of "puffs" as it exits the front of the pads. That could be what you are hearing. The wavy Martas don't do it because there are no holes to entrain the air. Find rotors with lots of tiny holes, or holes big enough that the hole is never wholly covered by the pad.

  5. #5
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    Quote Originally Posted by tscheezy
    The issue is probably this: when the rotor hole enters the pads, it carries with it the air inside the hole. The rotor and pads are warmer than the air entrained in the hole, so the air expands and sort of "puffs" as it exits the front of the pads. That could be what you are hearing. The wavy Martas don't do it because there are no holes to entrain the air. Find rotors with lots of tiny holes, or holes big enough that the hole is never wholly covered by the pad.
    This oddly makes sense!!!!!

    It would explain the higher speed needed to make it happen (more brake force needed.) I don't get it just bouncing around the court on my bike with my daughter.

    I would also explain the different sounds with different rotors.

    I did hear this on someone's bike coming down a hill I was going up recently.

    Now the question..................................
    How would you resolve this?
    The first thought would be to cut a vertical channel in the pad (perp to the rotor movement) My thought was this would let the hot air escape. I could try this with a nearly worn set of pads. So, if it doesnt work, I wouldnt care much.
    Lead by my Lefty............... right down the trail, no brakes.

  6. #6
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    Cutting a channel in the pad worked

    I used a hacksaw and cut a channel halfway through the existing pad material from the top to the bottom of the pad. I couldn't feel any difference in braking. In fact, I had one of my better downhill days.
    Lead by my Lefty............... right down the trail, no brakes.

  7. #7
    No, that's not phonetic
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    My recommendation would have been an iPod, but your method worked too.

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