I'm just doing some finessing on a design that features the Shimano SP-7400 seat post. It is only 200mm long so imposes some considerations on the design. I've seen the seatpost insertion dimension here http://www.bikecad.ca/seatpost_insertion but as part of modelling the seat post itself, I wonder if a minimum insertion value would be useful on the seat post design (62mm in this case)? I appreciate this is most likely only relevant to somewhat unusually short seat pillars.
Just a thought :)
Cheers - Robert...