ok, so against sound advice and my better judgement, i rigged up a surly singulator on an old vert-dropout roadbike. seemed to be working ok after several hours of riding. this morning, i wnet over a train trak and the chain jumped off. i figure it was due to a bit of stretch? but, i couldn't get the singulator to hold the chain where it had been, i had no cone wrench, etc...sooooo, i used a piece of wire to secure the singulator arm to the chainstay. not a good idea i know, but i needed to get home and get to wrk. i was pedaling easy and then jumped quick to make a light and the chain just snapped and wrapped around the cog and i went into a skid and walked home. i know very little about the physics of what is going on down there. i generally ride a regular track bike, but had this frame lying around and rigged it up. can someone tell me, in laymen's terms :O), what happend that caused the chain to snap, and any ideas that might make this setup work w/relative safety. i use front and back brakes on this bike for just such and emergency, i don't skid it at all. i would really like to make this setup work. thanks very much.