The Chainlink

I'm declaring open season on my seat post.  I am looking for a skilled and brave individual who can pull it from the frame.  It's a thick-walled aluminum post holding fast to a steel frame with a mangled 3/4" nub remaining above the collar.  

Already attempted:
1.  bolting 14" wrench to seat post and hammering to twist
2.  twisting w/ 36" pipe wrench
3.  hammering in
4.  lopping off the post 3/4" above the collar and slicing vertical cuts into the post and folding over.  (only managed to successfully cut through about 2" down.) and drowning it in penetrating oil.  

Let me know if you want to give it a whack.  If successful, I will of course heap beer and cash on you.  


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mattbikes1 said:
Have you considered a bike shop? I am sure they could put the bike upside down with the seat post locked in a vise and get that sucker free.

Careful. This is exactly how I ruined a Nishiki frame. It's easy to apply too much leverage, causing the seatpost to snap off, possibly inside the frame (which is how mine died). +1 on the Sheldon Brown link. Try ammonia or PB Blaster if you wanna get medieval.
If all else fails and you or someone you know are well versed in the Sawzall Fu, you can remove it by very carefully (!!!) cutting the seatpost lengthwise along its inside circumference. Be forewarned that this requires steady hands, plenty of patience and frequently stopping to check your progress as to prevent slicing into the frame.
i had similar problems with stems stuck in steerers... result of their owners not covering the headset while riding wind trainers (sweat in the works... yukk-a)

Tried beating and twisting, sawing- not good... Best luck was with Liquid Wrench and about 2 days' soak.

Ammonia may be worth a try. i'd avoid the coke thing for reasons already stated. i also might try a propane torch, slowly heating up the post stump awhile and then trying a vicegrip twist on the post. i've found a little applied fire can work wonders if you're very careful about paint and any old oil that might be around the area in question. WORK OUTSIDE.

When you get it free, grease the snot outta the replacement.
This may have been true at one time but there are products out there that attack AL oxide now.

You are correct that is the corrosion taking up extra space that makes stuff stick and if you can ditch that you can get the post out but it can take lots of effort or heat to do it.

Ammonia is supposed to work well and I know people who have had good results with AL but I have always had better luck with other products.

Alan Lloyd said:
According to the venerable Sheldon Brown ...

"Aluminum seatposts frequently become stuck by corrosion also, and penetrating oil is almost useless against aluminum oxide. Fortunately, aluminum oxide can be dissolved like magic by using ammonia." whilst "For steel seatposts stuck into steel frames, where the problem is often caused by rust, penetrating oil can do wonders. If you don't have real penetrating oil, any light lubricating oil is better than nothing, but penetrating oil is made specifically for this purpose, and you should buy a can if you don't already have one."

See http://www.sheldonbrown.com/stuck-seatposts.html

I think I read somewhere (else) that aluminium oxide occupies twice the space that the original aluminium did, and that is waht jams the seat post in place. You need the ammonia, or something else, to DISSOLVE the oxidation.

Did Dana ever get his post unstuck?

 

I also have a bike with a stuck seatpost and was going to go to West Town bikes tonight to see what I could do to get it unstuck.  Any advice?  I also believe that it is an aluminum seatpost in steel frame.

 

There seems to be some movement, but I'm not really sure what else to do other than put it in a stand for leverage.

 

 

Try a spray called "Freeze Off". I bought at Autozone. Like a penetrating oil but seems to change the temp, and alum contracts at different speed than steel. Got one I had been fighting.

Thanks for the tip, I'll give it a try.

Ed said:

Try a spray called "Freeze Off". I bought at Autozone. Like a penetrating oil but seems to change the temp, and alum contracts at different speed than steel. Got one I had been fighting.

The Freeze off worked like a charm!!!  Thanks so much!

jamimaria said:

Thanks for the tip, I'll give it a try.

Ed said:

Try a spray called "Freeze Off". I bought at Autozone. Like a penetrating oil but seems to change the temp, and alum contracts at different speed than steel. Got one I had been fighting.

The stuff is GOLDEN!

jamimaria said:

The Freeze off worked like a charm!!!  Thanks so much!

jamimaria said:

Thanks for the tip, I'll give it a try.

Ed said:

Try a spray called "Freeze Off". I bought at Autozone. Like a penetrating oil but seems to change the temp, and alum contracts at different speed than steel. Got one I had been fighting.

Brilliant.

 

I'll have to remember Freeze-off as an option the next time I have something REALLY stuck.

 

How much of the can do you use?  I'm assuming it is more than a squirt or two to make the magic work.

 

I've also never heard of using ammonia to dissolve Al-oxide.    I've had issues in the auto shop with Al rims sticking to the hubs and NOT wanting to come off.  It's like they are welded together and it is just a surface contact -not like a seatpost INSIDE the seat tube which is 10x worse.

 

The saw trick is something I've done more times than I would like to admit on stuck fasteners and it often works but is labor-intensive.

 

This is a great thread.  I'm glad it resurfaced so I could read it.  A happy ending makes it all the better.

I certainly didn't use the whole can.  I was very liberal with applying it though and was usually able to get half an inch up at a time before reapplying.  I probably used less than a quarter of the can though.

 

I've also heard about the ammonia trick, but you're supposed to remove the bottom bracket for it to work, and I don't know how to do that.

 

This seatpost wasn't really fused, it had lateral give, but the cold and lubricant seemed to help to get up it vertically.  The can was $4.99 at Autozone.

 

 

So the seatpost would spin a little  but not move up or down...

 

Strange.

 

What did the post look like after you got it out?  Were there any signs of heavy Al corrosion on the part that was inside the frame?  Were there any deep grooves in it from sand/grit inside or bad rust/galling on the inside of the frame?  Did you do anything to the frame itself after you got it out to clean it up before putting a new seatpost inside?

 

I've been known to run a brake cylinder hone up and down the inside of the seatpost tube to clean it up and get rust and corroded burrs out -this is especially important if you are going to put a longer seatpost in than what you had or will be lowering the seat any.  It's that lower section where it'll grab if it is rusty.  Also, if it is bad inside you are going to scratch up your seatpost even if it doesn't get stuck.  It looks sad if you raise your seat to see those tell-tale diagonal scratches on the part of the seatpost  that is sticking out higher now.

 

It is also very interesting to me that the freeze off product would let it come up a bit then get stuck again until another application was sprayed on.  In my experience once a seized item starts moving it'll either keep moving or it a sign that it is fatiguing and will very soon break apart/off.   The fact that it would get stuck again seems to show that there is actually something to this "freeze" thing and not just marketing hype.  How cold does it really get???  Any compressed gas/aerosol will get colder when it expands when sprayed.  But having it be cold enough to actually really do any good would be like using liquid nitrogen or something like that.  Weird...

 

As for removing the bottom bracket.  It's really not that hard at all to do but you really need some specialized tools on most bikes.  A crank-puller to get the crank arms off to start, and the correct wrench(s) for you particular type of bottom bracket come to mind.  If you have the right tools it really isn't much of a job.  Once apart it should really be cleaned and regreased before putting it back together while it is apart and replace any loose ball bearings too if they aren't the sealed-type.

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