OK, so on to the quest of improving the seat post. The only thing I can think of is to take a carbon fibre post which I understand would be stiffer and maybe have some better self-damping. So I am going to make a telescoping seatpost, with the top portion a 27.2x400mm long CF post, and the bottom an aluminium sleeve with QR.

Are there other suggestions for making the post stiffer?