#2: So a lot of what I was saying had to be confusing. I thought you have a Thud on it.

#4: I rode the Mini to work again, with the Nylon bush installed instead of an elastomer, and this time there is no doubt: The seat post is doing the bobbing. From this I thought that the nylon bush instead of the elastomer caused more pedal bob. Was I wrong on this?

#5: I was trying to seperate the Thudbuster from the actual seat post. Since the Thudbuster is non-existent, this is a ridiculous statement.

Basically, what I was trying to do is lay out the known information, not tell you what the known information was. I was screwed up on the Thudbuster portion, so it was good to get that sorted.

Ultimately, it comes back to stiffening the seatpost. I doubt if there is going to be anything that you can put on the inside of the post that will greatly affect it. Have you thought about trying to sleeve the outside of the post? If you could machine an aluminum tube for an interference fit and then stick the seat post in the freezer and the tube in the oven, then you could probably drop it on and end up with a super tight fit.