A few months ago I got a broken Cipollini RB1K from a friend which needed a carbon repair on the frame. The repair worked like a charm and so I was riding around with the bike for quite some time even tho the seat was way to low for my height (196cm).
I was looking around for an aftermarket solution but couldn't find anything suitable so I decided to design something myself.
I ended up copying the original shape of the seat post head so I can reuse the original seat clamp and parts. For the insert, I designed a base which screws into the old carbon bracket which is somehow ceased and not removable from the frame post anymore. Onto the base insert I can now stack up to 5 x 10mm spacers. The seat post head is then screwed down into the seat post base with a long M6 screw to properly sandwich the stack.
I did some stress analysis for the setup with an impact force of 4000N and the stress in the titanium does not look bad at all. Only the screw is at its limit.
The whole seat post is titanium 3d printed by JLPCB for 170€.
I did some riding with the new setup and it seems like the whole assembly is rock solid. The 4000N were probably a bit on the conservative side xD
Let me know what you guys thing about this and if I could have avoided all the work with some aftermarket parts I could not find haha.
Also if somebody is interested in this to safe their bike from getting thrown away, let me know. If people show enough interest, I might make it open source available.
by messsner