^^ I dunno about using IEM's while riding...I mean, I don't ride with music, but I used to be a huge audio buff and back when I still had Shure E4's those things blocked some serious sound. I've contemplated riding the MUP's with music, and I'll probably do it once I get my hands on a new MP3 player. But with IEM's? It's tentatively on my "things to try before I die" list.