Did you figure out what is up with the fix gear side?
The owner walked me over the procedure to tighten chain, but I didn't try it yet. He said the cogs have the same circumference but something bout I have to loosen chain ring, and sping wheels, and "walk back" the wheel a little at a time while tightening it down.
Mentioned something bout how all chain rings aren't perfect etc something bout float etc... He owns Guy's Bicycles and this is his bike and that whatever he said to do works... so I guess he knows what he is talking about?
I'll try it tonight.
EDIT: The procedure does pick up some slack and it worked a little until I saw the cog say 17T!!! haha. So he's sending me an 18T now, which it is suppose to be.