Bravo McDave and everyone! Saved me from scratching my head endlessly on this one.

Personally, I think these were a very clever idea. Wouldn't it be nice if we could use a small simple tool to quickly remove ANY modern cassette outside of our workshops.

If I did this right, here are 3 photo attachments showing how even the smaller diameter freewheels can be easily removed... AND... without even taking off your quick release skewer:

1. With the removal tool set on the knurled freewheel lockring.
2. Hub with lockring alone attached
3. Hub with the lockring removed to show the cross-threads.