I had the same problem with the Blackburn mirror... one fall and it's toast. It happened in mid-tour once and I replaced it with a no-name mirror from a K-Mart type store. It just clamps on to the handlebar. The mirror is attached to the clamp by a flimsy, bend-it-to-shape plastic coated wire. Doesn't sound good and it wasn't. It vibrated so badly it was impossible to see much of anything. However, I stiffened the connection by wrapping it with solid copper electrical wire (14 gauge, I think) and topped all that off with some plastic electrician's tape. Works like a champ. That was four years ago, and I still have the mirror. Just have to replace the tape when it gets too ratty to tolerate.