Mechanical disc brake scratching noise The rear mechanical disc brake on my MTB makes a sharp intermittent scratching sound every time the wheel gets to a certain point in each revolution. The disc is true, so that is not the problem for sure. The brake is a Hayes MX5. Any adjustments I can make? The brake pads are pretty close to the discs, but I don't think they should be rubbing like that.
I have found before that if you decide to do the quick release up tighter than usual it can tighten up the bearings a little too much and you might hear a fairly regular noise as the wheel rotates. I'm not sure I would call it a 'scratching' noise, but maybe that's it. Try a looser quick release adjustment. If the noise remains the same then you can rule this idea out.