Seat post stuck in frame

[bertbean]

Use Caustic soda. I had the same problem. I tried drilling the post and putting a bar through it, clamping it in a vice, soaking it in wd40 and also tried cutting down the inside of the tube. There was at least 10 inches inside the frame and it wouldn't budge.
I stripped the frame down and plugged the hole inbetween the BB casing and the seat tube with vaseline and then wedged an old innertube in as well. I also put vaseline in the bottle holder holes and replaced the bolts. Then I mixed the caustic soda with warm water and poured it down the seatpost (I'd cut the top off to cut down the inside). When the 'steam' and fizzing stop, empty it out into a bucket and pour more down the seat post. I did this 2 or 3 times a day for about a week and a half. Every day I got the grips on it and tried twisting and eventually it went. The post was only about 4 inches long when it came out and there was a load of sludge in the bottom of the frame. It might take a while but it costs about £3.

Warning. The info I read said that Caustic soda doesn't damage paintwork but where it was running down the back of the seat tube it stripped it back to the metal so don't blame me if it does the same to yours.

Good luck and keep going at it. It was a really good feeling when the bugger finally gave.

 

[bm0p700f]

Melting the ally seat post with a welding torch takes 10 minutes and will ruin your paint. Sounds like caustic soda will do too and its nasty stuff as well.

I prefer melting myself and its a good excuse for a new paint.

 

[Dick Scruttock]

Sent it into my local engineering place today. Should have it back without a stuck seatpost within a few days.

 

[Dick Scruttock]

They got the post out. Took 2 guys over a hour to remove it because of hiw far it protruded into the frame. The shim must have been pretty long.

 

[coomber]

Photos!

 

[rody]

For future use, here's the best remedies...

I have done dozens of stuck seat post removals as a service to local shops.

With the AL post you are facing...fixture the frame in the lathe and bore it out with an under sized bit. It will likely break free before you are fully through.

A close friend and builder, John Upcraft of Hubcap Cycles had made some informative blog posts on the subject, showing a few of the methods that are successful.

Al seat post example, typically about 20 minutes...

http://hubcapcycles.blogspot.com/2009/1 ... parts.html

and a visual of cutting the post into sections...took less than an hour to remove

http://groovycycleworks.blogspot.com/20 ... r-day.html

Steel or Ti example, about an hour to accomplish...

http://hubcapcycles.blogspot.com/2009/1 ... r-fat.html

cheers,

rody