Sounds like that's a lot of post in the frame. The common corrosion bonding often starts at the post's bottom end, deep in the seat tube on this bike. It would be nice to know where this point is as to limit any efforts to the area needed.


A few comments. I find this sort of effort is easiest done with another person, a bench vice, serious pipe wrench and the frame as bare as possible


There are so many guides to this on line, Sheldon brown's site is a good start to learn the well known range of attempts. I've had no luck with ammonia soakings the two times I tried it. Never used caustic chemicals yet although this seems the best to also not damage paint. If the paint wasn't a concern (as in an up coming repaint) then I'd likely just melt the post out with an OA torch. Andy