Originally Posted by
danmerk23
Can't you thread on a fixed cog on the freewheelside and then thread on a bottom bracket lockring right behind it? I thought they were the same threads as a cog.
You can, but the threading on a proper fixed hub is a left hand thread to prevent unthreading. Using the BB lockring has the potential (however low is up to you) to become loose since they are both right hand thread.