Tried lots of WD40. Tried lots of twisting the wheel with the seat wedged into something. Even tried soaking the thing in coca cola, which the internet told me to do. Followed by more attempts at twisting.
About to give up…
Maybe, remove the saddle and try hammering the seat post downwards into the tube. That should loosen it .then you can pull it out.
Hope this helps.
Keep soaking it for a few more days if you have the time. If it still won’t release try heating the frame neck with a propane torch. Heating and cooling will break the bond but destroy the paint. Good luck.
I had a seat post stuck in a frame earlier this year. Here’s what I did:
- Took the seat off of the post.
- Turned the frame upside down and rested it on an elevated surface. The idea was to have the frame completely supported by the elevated surface so the seat post is not touching the ground.
- Bang down on the seat post right where the seat bolts would go with a hammer until it comes loose.
I had a square crown so it was easier. If you have a round crown you might consider a vice.
The frame I used for my commuter bike had a seriously stuck seatpost when I got it. After twisting, beating, chiseling, and a couple of weeks of Coca-Cola, this was what finally got it:
(That was for an aluminum seatpost in a steel frame. It might be harder to avoid damaging the frame if the post and frame were both steel.)
^This seems like the best advice.
You would be better off using a penetrating oil like liquid wrench instead of WD40. Let it soak, or if you are impatient you can lightly tap the seatpost with a hammer as you wait for the oil to do it’s magic. (Vibrations help the oil get between the parts quicker.)
If there’s some sort of a burr between the post and frame, you can twist it all day but it won’t want to come out. If the gentler methods don’t work, I would go to the upside-down method, with post pounding. Depending on your frame design, you may also be able to take off the wheel and access the bottom of the post through the bottom of the frame, to pound downward.
I put wheel between legs and give it a good twist once seat clamp is loose
Actually, if you can ride it as-is, maybe just take the clamp off. Then it will come loose, and dump you while you are a long way from home… 
^+1 That is so true!
Old trumpet players’ trick for removing stuck mouthpieces:
Tie the trumpet firmly to something that won’t move.
Put a loop around the mouthpiece and tie the other end to something else that won’t move either.
Now, using a bar of some kind, take a loop of the string that is attached to the mouthpiece and twist it until the string becomes really tight. What you are doing here is exerting a gradual but firm pull on the mouthpiece.
Leave it overnight.
Adapt this technique for the uni, and use lots of penetrating oil.
WD40 is water dispersant which also happens to have lubricant properties. A proper penetrating oil will be more suitable.
You guys have it all wrong!
You need to follow the Nurse Ben fool proof method for overcoming a stuck seatpost; this method also works for a myriad of other unicycle problems:
Buy a new unicycle
So this must be an older steel frame and steel seatpost, right?
Try a pipe wrench on the seat post, frame in a vice with padded jaws, go for it!!
FYI, there is a grease that has a silica suspension that works wonders for keeping clamped bike parts snug without creating a locked up mess later: http://www.finishlineusa.com/products/fiber_grip.htm
Yeah, just borrow my time machine and do that.
That’s how I got mine loose.
Why dont you lads run a lube on some sort?
I would expect a 100% success rate with Nurse Ben’s strategy.
Scott
And a refund if it doesn’t work…
Hey, bristlecone have you had any success yet?