Chain skip with tensioner
I'm a long time single speeder but this is the first time I've had a bike with vertical dropouts. My problem is when I'm pushing hard, usually getting going at an intersection, I experience that disconcerting POP sound of my chain skipping a tooth. I'm using a 16 tooth freewheel and a short cage deraileur locked in place with the limit screws for a tensioner. Short of swapping the freewheel for a bigger one, anyone have any ideas about what I could do? I can't imagine a "real" chain tensioner (except maybe a Surly one in "up" mode) would do any better job of wrapping the chain than what I have now.
Since you are using a freewheel, the tension provided by the deraileur should be sufficient (it is for gear bikes), Is the chainline nice and straight? How old is the chain? How old is the cog?
I'd guess you need a new chain. Chain stretch means that the force is concentrated on fewer teeth and consequently the forces on those teeth are higher. Same thing with a worn cog or chainring.