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Old 04-04-14, 11:14 PM   #1
Elle Zed
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disc brake scraping sound

I had to change my front tire and now when I put the wheel back on, as soon as I tighten the pinhead skewer, a metallic scraping sound starts coming from the disc brake.

I'm pretty sure it's not the disc rubbing on the brake pads, but rather the "arms" of the disc are rubbing on the "housing" below the pads. (Sorry I don't have better terminology). I'm starting to see shiny metal on the housing where the coating of dirt is getting scraped off. These are Shimano M495 disc brakes.

I've tried seating the wheel/axle ever so slightly differently in every direction, and each time, the wheel spins free until I tighten the skewer, at which point the scraping starts again. Any tips or tricks?

Last edited by Elle Zed; 04-05-14 at 12:27 AM.
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Old 04-05-14, 06:41 AM   #2
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Post some photos.
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Old 04-05-14, 07:06 AM   #3
rydabent
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You may just need to reseat your wheel. Or my may need to readjust the position of the caliper. Maybe when the bike was built, the wheel wasnt seated right, and the caliper was adjusted to the faulty position of the wheel.
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Old 04-05-14, 10:03 AM   #4
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Originally Posted by cobba View Post
Post some photos.
Difficult to get a good photo but here is the brake with the scraped part at the bottom. You can see the "arm" of the disc about to hit the spot.
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Old 04-05-14, 10:20 AM   #5
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Cable type .. You got a specific caliper maker ? name it.

get the brand maker's website to learn where you make the pad adjustments


pad or installation Adjustment, or bent rotor ... Next ...

Last edited by fietsbob; 04-05-14 at 10:27 AM.
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Old 04-05-14, 08:28 PM   #6
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Difficult to get a good photo but here is the brake with the scraped part at the bottom. You can see the "arm" of the disc about to hit the spot.
That looks like wear on rotor that's caused by the pad.

Does the rotor have the same wear on the other side ?

Post a photo of the other side of the brake.

Turn the bike upside down, shine a torch in/at the brake caliper/rotor, turn the wheel slowly and look to see if you can see where it's rubbing.

How much have the pads worn down ?
Do you ever adjust the pads as they wear down ?
Do you know how to setup and adjust the brake ?
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Old 04-06-14, 03:04 PM   #7
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Thanks for the tips - I'm not confident enough to touch my disc brakes so I took it to my LBS. The mechanic adjusted the calipers - loosened the skewer, loosened the calipers, held the brakes then tightened everything. Sounds like what rydabent said.
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