Originally Posted by
alcjphil
First thing to check on any cassette with an 11 tooth small cog is that the lockring is made for 11 tooth cogs. This is easy to miss. A lockring designed for 12 or larger tooth small cogs is too large in diameter for an 11 tooth cog and will cause exactly the symptoms described
^^THIS^^ Don't ask me how I know. The cassette lockring should have either '11T' or '12T' or something very close to that printed on it to tell you which small cog it's designed to be used with.