Originally Posted by
orange leader
what type of chain are you using. If you have chain made for multiple gears it may be too thin for the surly cog. I may not be seating well onto the teeth of the cog, as single speed cogs are fatter than the cassette cogs. Try a single speed chain (if you haven't already).
got a 1/8" chain on there thanks for the try though = ], keep the suggestions coming people