Bicycle Tutor

Hi i have a problem with my saddle post, as it is stuck wont come up wont go down, any idears how to free it.

This is one of the worst things that can get stuck, it is even "more fun" than a thread on freewheel that won't come off. My suggestion would be to follow:
http://www.sheldonbrown.com/stuck-seatposts.html
good luck, you need it.

This is truly the most powerful product I have ever found for metals that seize to each other:
http://www.pbblaster.com/PB_Blaster.html

Most of the time my response is, "So, you needed a new frame anyway right?"

Just kidding. It is possibly the hardest thing to get unstuck.

I usually skip steps 1 and 2, involving trying to turn with the saddle attached (Which can bend the rails), using a pipe wrench with rubber padding (Which can deform the post), and go straight to 3.

I wrap the post in a cold compress, for about 25 minutes, or as long as the compress will stay cold, and then get the CO2 cartridge and blast it. The entire cartridge. And usually that's enough to shrink the metal to the point you can take it out.

I usually go to a kitchen supply store or a paintball shop to get the cartridges. But since this is likely the only time you'll be doing this, just buy a couple from the LBS.

You have a picture of your bike you can put here in the forum? Or list the make model?

I have to search the archives of the frame builder mailing list, there was a discussion some days ago, I think I remember that the solution was (for steel "welded" to aluminum) applying ammonia to it. It will dissolve the aluminum but not touch the steel.

The ammonia trick works, but only if there is sufficient space between the seat post and the frame. if its REALLY corroded and stuck in there, there may not be room for the ammonia to do its thing.

That, and the ammonia you buy at the hardware store is an aqueous solution, since ammonia boils at -28 Fahrenheit, and the oxidation of the aluminum releases hydrogen, and if the OP smokes, this might not be a great idea in the basement.

From what I understand, quite a lot of hydrogen is given off, and it's not like you can smell it, its colorless and odorless, so you would be looking at a situation where a well ventilated area is required.

My two cents? Sacrifice the seat post and squish it in a bench vise, then turn the frame ever so slowly back and forth to release it. Seat posts are cheaper than frames. Well, some are.

With everything said above I am wandering what kind of Bike it is because of the type of frame. If it is a lower end MTB frame then there is bottom access which would help immensely. Could do a combination of the ammonia or pbblaster (depending on the metal make-up), hair dryer and CO2, then quickly yank like hell method! That don't work vise time!

I've never heard of the ammonia method before. Good to know!