squeal

I know me again lol. Took the bike to work today after installing the new rear Galfer rotor and dp404 pads. After 10 miles or so it started making a loud hum when coming to a stop? Got home and took it apart, cleaned it all again including the pins and the metal thing that sits on top. I scuffed...

Not all the time but now and again I get this annoying sqeel from the rear brakes. It is kinda embarrassing actually. I did put on new pads in the spring when I first got the bike. I thought it was just because they were new. What is the main cause of this ! Can I do anything to the...