I have a basic flip flop wheel with one side threaded for track lockring, the other side straight freewheel thread. I am using the side with track lockring threads and feel secure with it. When I bought the next smaller cog, my LBS put the old cog on the freewheel side using a bb lockring. I realize that this is not an unusual setup, but I have never had the confidence to use that arrangement nor have I really had a need to. Is anyone actually using the cog/bb lockring setup on a regular basis? Has anyone ever had one come loose? I have always figured that it would be VERY difficult to get a bb lockring locked tight enough against the cog to reliably withstand the stress of resisting the forward motion when stopping. I do know how to tighten lockrings/locknuts against each other. If these were two nuts that I could get box end wrenches on I might feel pretty good about it. I am not as comfortable with being able to get a good firm grip on the notch and tooth arrangement of a bb lockring and spanner, even with the Park that engages three notches.

Any thoughts on this?