I've put together a winter hack bike for commuting. Based on an old Peegeot road frame with mudguard clearance and eyes.
700c wheels. To make it even more bomb-proof, I decided to go single speed. 16 tooth cog at the back.
To my surprise it has been hell to set up. the chain keeps jumping off. I've tried playing about with the chain tension, but it won't come right. I tried a chain tensioner - like a single jockey wheel on spring tension, but then the damn chain would skip every time I put any hard pressure on the pedal stroke.
I expected a single speed to be a doddle to set-uop, but the bike is barely rideable.