Should I be able to hear my disc brakes dragging?

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Veda · #1 Unread post by **Veda** » Sat Jul 28, 2007 2:22 pm

When I have my bike up on the centerstand and rotate the wheel I can hear a quiet metal against metal rubbing sound. I think it is the rear brake dragging. I've been told by other people that it is normal for disc brakes to drag a bit and maybe it is by design to keep dirt and debris from getting between the brake and wheel.

Does this sound right?

(for those not keeping track is a 2007 ex250 with only 1,800 miles)

BuzZz · #2 Unread post by **BuzZz** » Sun Jul 29, 2007 3:05 am

Yep, sounds about normal.

Quiet is fine, when it gets loud or pronounced, then you may have dragging issues. But it sounds like your O.K.

Shorts · #3 Unread post by **Shorts** » Sun Jul 29, 2007 4:11 am

Veda, both our bikes do have the sound you describe and they are in good shape. Its pretty normal. But if it changes to uglier, louder noises, then maybe it needs some work

jonnythan · #4 Unread post by **jonnythan** » Sun Jul 29, 2007 1:42 pm

Unlike drum brakes, which have a spring return system for the pad, the friction of rotor against pad is the only mechanism there is for creating separation between the surfaces.

If you use the brakes to come to a stop, then let go of the brake lever or pedal, the pad will still be touching the rotor. It usually takes quite a few revolutions to have the surfaces touch enough to push each other apart so that they're not making much noise.

This is the case for all disc brake systems, whether on bikes or cars.

In other words, it's perfectly normal.

#5 Unread post by **Sev** » Sun Jul 29, 2007 3:36 pm

The seal around the pistons will actually pull the piston back into place once the hydrolic pressure is released (lever released).

But that doesn't change the fact it's a normal noise.

Now... if it were loud, or if it starts and stops eg - makes noise half the rotation, and is quiet for the rest then you've got a problem.