Donhou Bicycles

It's been done for the clean lines - no seatpost bolt, and a seat tube almost all the way to the saddle. The seatpost is just a little nub. Same reason that we've gone for hidden cables all round.

I'd look into sealing the opening to the seat tube. Quil seatposts have been know to devolope squeaking. ingress of grim into the unclamped seat tube opening and the tiny amount of movement afforded from clamping at the very base of the post, are thought to be the reasons.

Look at the Race Won pic and zoom on the seatpost.
http://www.qoroz.co.uk/race-won/