I had the same problem on my track bike. The lockring was wide with no taper and the outer links on the 1/8" KMC chain were deep at the bottom to help guide the chain on the sprockets, such that it was hanging up badly on the lockring. I was doing an overgear workout on the track, and had to remove the lockring and tighten the cog a bunch so it would not unscrew. Needless to say, when I was done I slowed down real easily.