It's quire easy to make such a seat post from a standard Kalloy aluminiu m seat post. Just made a temporaty one for the AeroTour within a few mun ites when I needed one. The thing about using an expanding seat post is frames designed to use them have reinforced seat tubes. Look at the Aero Tour design and you will see that where my expander operates is right wh ere the hellenic seat stays cross the seat tube. I put a sleeve inside t he tube (the seat post is a 26.0, where the original seat post size is 2 7.2) and also put the "plates" on the seat tube where the expander is wo rking and where the stays cross the tube also. Super reinforcement that guarentees nothing will ever happen to the seat tube on account of the e xpander; all cleverly hidden in the design of the frames. That's thinkin g ahead!
I would use a sleeve in addition to your expander post if you stick it i n a standard frame. It will need a cut along it's length to work best.
Brian Baylis La Mesa, CA
La Mesa, CA
Here is a tough one, I got a lovely 1930's (original paint) frame with
the seat lug broke at the binder bolt area. Did any one make a seat post
that used an expansion bolt to tighten the seatpost rather than a binder
bolt at the frame? Hopefully that makes sense. I am looking to see if
they exist then locate a size.
San Luis Obispo, Ca.