Pulling out a stuck steel seatpost from 1950's road bike.

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Pulling out a stuck steel seatpost from 1950's road bike.

Postby dddd » Fri Feb 10, 2017 8:48 pm

I've been working on this bike's seatpost problem for a week now, it's still stuck!

I put a heck of a pull on it today, close to 3000lb tension, and it moved just a half-millimeter, that's better than nuthin'.

I'll soak the post from both ends with PB Blaster penetrant, than have another go in a couple days.

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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby to the beach » Fri Feb 10, 2017 11:40 pm

If you're going to repaint, a torch around the length of frame's seat tube may work.
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby Tomcat65 » Sat Feb 11, 2017 12:08 am

If it moved at all, you have this thing whipped. Stay at it, just don't bend that frame in the process!
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby BicyclePhD » Mon Feb 13, 2017 8:49 am

You can also try using Coke to soak it as well pour it in from the BB and let the frame sit upside down.
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby dddd » Mon Feb 13, 2017 8:07 pm

Thanks for all the encouragement!

Turns out that an over-sizepost had been forced in, there was no rust on it inside.
It moved an inch, slowly, as I pounded on the seat tube 300 times with a hammer and block of wood, all while tensioned to 3000lb pull.
Then it popped out. These frames get reamed near the top after the frame is brazed together, and the diameter inside gets smaller below the reaming. It might be a factory post that just got pounded in too far, but it should have been able to just slide in that far if the reaming went in as far as the post might get lowered.

I'm glad that I remembered to snap a photo while the frame was still outside!

Image
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby jasnooks » Mon Feb 13, 2017 8:23 pm

dddd wrote:Thanks for all the encouragement!

Turns out that an over-sizepost had been forced in, there was no rust on it inside.
It moved an inch, slowly, as I pounded on the seat tube 300 times with a hammer and block of wood, all while tensioned to 3000lb pull.
Then it popped out. These frames get reamed near the top after the frame is brazed together, and the diameter inside gets smaller below the reaming. It might be a factory post that just got pounded in too far, but it should have been able to just slide in that far if the reaming went in as far as the post might get lowered.

I'm glad that I remembered to snap a photo while the frame was still outside!

Image

Lol, sometimes that's what it takes!
Cheers to a job well done!
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby Tomcat65 » Tue Feb 14, 2017 7:59 pm

Looks like things got a lil spiritual
Not many people understand the struggles :P
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby dddd » Tue Feb 14, 2017 9:33 pm

I was starting to become convinced that the devil put that post in, to stay. Had no other idea what could be goin' on with it.

But it was like pulling a rubber hose off of the spigot of a carburetor, sometimes the harder you pull, the harder it grips, and the seat tube was sure gripping the post as I put over 3000# pulling them apart.

Next time I'll start by welding a square metal plate on top of the post, then twist it out with a vise or giant wrench.
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby frictionshift » Sun Feb 26, 2017 6:48 pm

dddd wrote:I was starting to become convinced that the devil put that post in, to stay. Had no other idea what could be goin' on with it.

But it was like pulling a rubber hose off of the spigot of a carburetor, sometimes the harder you pull, the harder it grips, and the seat tube was sure gripping the post as I put over 3000# pulling them apart.

Next time I'll start by welding a square metal plate on top of the post, then twist it out with a vise or giant wrench.


If I had known that you wasn't interested in keeping the seat post...

I might have suggested to place a solid steel rod down the tube and twisting the seat post with a heavy duty pipe wrench.

It just looked like your idea was working well enough to save the life of that old seat post.

The pipe wrench would have burred it at best -- and probably caused bends and twists.
I'm the old man you see on the bike.
I love my 10 speed, but can't resist taking my 20 inch for a spin.
So I bought this cheap bike to use for donor parts, but find myself trying to build it back up now...
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Re: Pulling out a stuck steel seatpost from 1950's road bike

Postby dddd » Mon Feb 27, 2017 6:55 pm

Yeah, If I could have put in a solid rod and maybe gripped it in a vise with rounded jaws or between V-blocks...

I had already flattened it a bit with pliers anyway, so it's trash now.
It was fully 1mm too big for this frame anyway! I could only get a 25.8mm post to fit and clamp properly, but the post that came out was 26.8mm!!! Hard to believe.
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