The Kool Stop black compound is less likely to squeal than the salmon compound, if that's a factor. You may need to toe them WAY in, if the brake arms have some play. I had a similar problem with Avid Shorty 4 brakes, just too much play and it couldn't be adjusted out. With black Kool Stop pads toed way way in, the squealing finally was gone and the braking was good.