First, let me say that yes I'm a noob here to this forum, but not retarded (though some I know may beg to differ). I have done a FULL search here on this board and have found no similar experiences/technical help listed on the REAR brake. So, yes, I did search before posting this question.....

The question is what might be causing a crunching/grinding sound from the rear brake intermittently? It does not elicit the noise when applying the brake during flat, normal riding conditions. It seems to make the noise most when braking while going downhill at relatively low speeds or on flat ground only when braking hard.

The bike is an '07 with 3000 miles (just bought it from original owner). The rotor does not appear to be warped or pitted, and the rear brake master cylinder has the appropriate level of brake fluid. The brake pads still have plenty of room for wear.

The thing that doesn't seem to make sense to me is that it doesn't make the noise every time the brake is applied. And no noise from the rear wheel or brake when riding (not applying brake).

Any suggestions/ideas/thoughts would be appreciated!

Thanks in advance,
a Masshole.....

 

Ha! Well, guess all I needed was a heavy duty water crossing! No more noise! This leads me to believe there must've been some crud in there somewhere. Though still kinda confusing why it was intermittent, but whatever!

 

Welcome to KF. My first guess was chain slap. Take care of that chain. Let us know how it goes.