Steven,
What is the diameter of that seat post? Or the wall of the tubing; is it sleeved perhaps?
Brian Baylis
La Mesa, CA
Just curious.
Speaking about internal expander seatposts, I have a 1940's Italian frame with cambio corsa that has one of these expander seatposts. After more than 50 years it still works and has not damaged the tubing.
--
Steven Maasland
Moorestown, NJ