Vintage Peugeot conversion help and tips please

Hi again - I am hoping that you may be able to help as I had no joy in Mechanics & Fixin'

I have recently converted my '89 Peugeot into a SS. I am running a 20t 1/8 freewheel on the back and my chainring is 52t 3/32. My chainline seems ok and my tension is also good. The problem that I have is if I increase the rpm which I pedal at then the chain comes off the chainring in the direction towards the frame. It is extremely annoying and I would like to get is fixed asap as it is stopping me from riding at the moment. Any help would be great...?

You might find that the best option is to get a 1/8 chainring. The chain will fit perfectly on it and should stop the chain from coming off. The only problem with this is that you may need to replace the cranks.

Sorry to jump in on this thread - I've just finished converting a mid 80's peugeot to SS and although everything' else is running fine, the cranks are on the way out so to speak.

Will a normal square taper crank fit?

Yeah, you should be able to. Check to make sure your current bb hasn't worn on the square taper section as this could cause damage to every set of cranks that you install. Also check the new cranks/chainring don't foul the frame. If they do then you may need a longer bb.