For my girl's 1975 CB400F squealing front brakes what i finally did was, on the non piston brake pad, take some clay (i used clay for rubbing paint before waxing but I'm sure many types will be fine) roll it into a thin worm. about 1/8 to 3/16" in diameter and about 2 inches long. make a ring out of it and put it on the backside of the pad (where the metal rests on the metal). what this does is allows the pad to oscillate on the raised bump of the pad but reduces the high speed vibrations. this lasts about 6 months or so, depending on how hard you brake. after the squeak comes back i simply remove the clay, roll it up and make it into a ring again. simple and clean.
the photo is after about 6 months of daily use.
