EDIT-- I just saw your recent post. It sounds like you have the right ideas. Good luck!
Originally Posted by
Spoonrobot
Put it in a vise?
If you're feeling daring, you can whack it downward to loosen it a bit more and then try to pull up.
How far down is the post? Can you grip it with the pipe wrench as close to the seatube as possible, angle the pipewrench upward so it's wedged against the post and then push up while rotating around to corkscrew it out?
maybe as a last resort.
Originally Posted by
Roamer2
If you don't care about the post, drill a 1/2" hole thru it & use a large screwdriver or something to twist it back and forth while standing on frame to pry it upwards.
No, don't stand on the frame!
hold the frame, and have the seatpost fixed in place. Now you have leverage that's unlikely to damage the frame.
From Park Tool repair guides. This will mangle the seatpost.
Remove the saddle from the bike. Remove the wheels from the bike. Mount the bike upside down with the post clamped in the hard jaws of the vise. This will allow the frame to be used as a lever. It may be useful to have someone pull upward while you twist the frame side to side. If the post is very tight still, use care not use the rear dropout for leverage as this may bend the rear triangle.
If you don't have a vise on a sturdy workbench, perhaps you could use a junk saddle (from the LBS?). Set the bike upside down, but you want the handlebars off the ground. Maybe a raised platform would allow the saddle to be flat on the ground and the rest of the frame and bars off the ground? Then stand on the saddle and twist the frame while pulling it up.