br0qn
Retro Guru
Cough, calipers, cough!
Could also be the black finish on the Dean post.
I've had several seatposts come in a few mm's over their supposed sizes, usually because of the finish.
I saw the bell and knew what your reply was about before I opened the thread!
If there is another bell with your name in it I know it's a link to calipers...