I have got the carbon seatpost stuck on my c'dale synapse carbon road bike. Lots of stuff elsewhere on www with suggestions for getting off, but I am not sure whether the interface is carbon- carbon, or carbon- alu. There is a metal (alu?) collar at the top of the seatpost - not sure if this cOllar is where things are stuck, or further down. As many of the methods are specific to the interface, not really sure where to start....
Any thoughts appreciated!
take it to a bike shop.
Try warming up the seatpost with something like a hot water bottle (don't use a hairdrier or hot air gun, under any circumstances) and cooling the seat tube with a bag of peas or similar.
Carbon reacts the opposite way to metal with changes in temperature and the expansion/contraction of the different parts may be enough to free it with a bit of jiggling.
Cheers folks