Thanks Mr McNally, I'm a bit puzzled, despite your description being very concise, about how and where the bolt goes through the chain :


"next, take the end of the chain that is dangling off the rear sprocket and bring it up and around the sprocket to meet the top chain run, and thread a suitable size, long and thin, bolt through a set of links to hold the loose end to the top chain run"


Is the top chain run the top guide that the chain goes across?
Once again, thanks, many views but yours is the only answer