So (I thought) I finished my SS build this week. I took it out for a quick spin around the block before I left for work. Started cranking on it pretty hard and the chain came off the ring and I ate s*** like never before. All scraped up, hit my head on the asphalt, etc. (No sympathy from wife).
Anyway, I used a Bontrager road crank and just removed the large ring so I'm running the 39 tooth. I've got a 13 tooth cog in the back from an old road cassette I took apart. I'm using what I believe to be a 1/8" chain from my spare parts box. The tension seems decent, but I'll try to put in a half link as soon as I can find one (frame has vertical dropout).
Now I'm asking your suggestions....is this a chain tension issue? Or is there a problem running a chain ring designed for shifting? (i.e. the teeth aren't tall enough?) Any guidance is appreciated.