Originally posted by shrimpx
what other kind is there? 
if you use a same-threaded lockring you better run some sturdy brakes.
The reason I asked is because as you probably know, alot of converted fixies use old threaded freewheel hubs and use bottom bracket lockrings to secure the cog which is obviously threaded the same way as the cog. In some instances if these lockrings are not locktighted, cog and ring can spin off...