Originally Posted by
Carbonfiberboy
Her chain had popped off the inner cog on a big bump and wedged itself between the cog and hub.
Couldn't happen to me - my cassette is machined at the back to fit on a 7s spline, and there just isn't room
It's a pity this trick requires a billet cassette; on Shimano cassettes the riveted part of the cog goes to a diameter too small to clear the hub.