I just had the 1k service and noticed how hot the rear disk was getting and how it had a bit of wear. I know of the sound you are talking about too....you can hear it when you put the bike in N and let it coast with the engine off. That is what alarmed me the most. The dealer said that the FDXBs all do that and that it was normal. Odd as hell, but normal? Oh well. I am keeping my paperwork for the service just in case something happens.

 

My issue only occurs when applying the brakes, never when just coasting, and it comes from the front brake, and not the rear...

 

My Wide makes that buzzing sound in the front when I start squeezing the brake; I believe it's a harmonic caused by the pattern of thru-drilled rotor holes in conjunction with the pads. Not sure if it's caused by the air[holes] interacting with the pads (like some kind of orchestral wind instrument), or whether it's caused by the hole-edges to pad harmonic (like a bow to violin string phenomonon). My Vulcan does it, too. If the sound bugs you, look for a replacement solid rotor that doesn't have the [cooling?] holes drilled thru the pad contact area.
I had an annoying pad-dragging sound at low speeds after I added my chrome lowers...so bad I'd feather the front brake to quiet it at low speeds. Went away when I installed the chrome caliper with new pads.

 

The three Harleys I've owned have all made a buzzing type noise in the front brake. I've never really tried to figure out exactly what causes it but it's nothing to worry about. If it bothers you, I really dont think there is much you can do about it.

 

Definitely I can live with it, since it is not constant. Just more concerned if it is in fact normal. I'm beginning to think it is. May have something to do with heat expansion on the discs since it happens after long highway rides. Will still check at dealer on my next service, but not as worried any more at this point. Thanks for the info..

 

Buzzing is caused by the holes in rotor they are there to let hot gas escape during breaking this reduces fade and improves stopping power.

 

Though mine is not a buzzing, more of a loud humming...

 

LOL dido on the locust Never woried bout it think it just the gasses escaping from the cross drilled holes like it was intended to do. One of the first things i noticed when i got the 09 bob. (I like the sound)

 

My brakes made noises until I cut the baffles out of my pipes. That seemed to fix the problem.

 

I had the same thing. Told my dealer and what ever they did fixed it.. Tell them while under warranty.