The seatpost on my old m4 stumpy is stuck.any suggestions on removing it.

seatpost in a big vice attached to something solid, use the frame as a lever.

then Coke, diesel, penetrating oil, or last resort cut the post off flush and either use a reamer or a hack saw blade inside the post.

Thanks pal,Al give that a try

Given the Royal PITA that sawing a post out is, especially on an alu frame where you are more likely to cut into the seat tube, I’d cut it off flush, slot it and put a new smaller seatpost inside – should be do able on 30.9

Same here on my genesis io & raceface seatpost, been soaking in plusgas for 2 weeks but still no joy, everything is twisting up but nothing giving. Liquid nitrogen poured through bottom bracket hole down the seat tube to be the next ploy to try & shock the joint.

Fella over on retrobike has a method involving a slide hammer that he reckons works well.