Last year we took our RT2 on the RSVP (Ride from Seattle to Vancouver and Party). This is a 185 mile ride over some flat terrain and some hilly terrain, but while there are some short steep descents there are no long steep descents. By the end of the trip the rear brake on our bike was squealing loudly although it was stopping the bike. Pads and rotors looked like new. I did some research and decided to replace the stock metallic pads with the organic ones. OK, not too hard a job. But after the replacement pads were in the bike continued to squeal. I was beginning to get irritated! I took everything apart and reinstalled the pads, but this time I noticed they felt "different" when they seated. This time no squeal at all. I now believe it is easy to get the pads into the holder such that they are not perfectly parallel to the disk. These parts are small and my eyes are not young anymore so it is easy to miss this. What caused the pad to be seated at an angle to the disk? Good question. When the bike was brand new a few of my friends with really good ears noticed a "whispering" sound from the back of the bike. I adjusted the pad out one click and the sound went away. On the RSVP I always alternate front and rear brakes to try to prevent fade. Maybe engaging too fast causes the pad to "jump" out of alignment. Bottom line is I don't know what caused it. I now believe the original metallic pads were OK if they had been seated properly. But the non metallic ones are working so well that I am not going to tempt fate by replacing them. We are a 330# team.