atypical stuck seat post: Andrew Muzi help!

[LF]

A friend's inherited bike (Specialized Sequoia) has a stuck seat post. (Steel bike, aluminum seat post). Currently, the seat height is too short for him. With the seat post clamp undone, I can rotate the post left and right, using the saddle for leverage. I am not able to pull the seat post out of the seat tube even a little bit (I marked it with tape so I could see).

This is a fluted seat post, not the original for a Sequoia. My theory is the seat post is slightly too fat for the seat tube, and the original owner banged it in to its current position.

Lubrication helped. Ammonia did not seem to help.

I would like to fix this tomorrow, Friday, for a century ride this week-end. (Cape Cod Getaway, MS fundraiser). My friend would like to take it on this ride for sentimental reasons. I'll try putting the bike upside down in a bench vice, clamping down on the seat post, and using the frame for leverage.

I hope to avoid cutting it off, and then hack sawing internally vertically. If I resort to that, are there now power tools to make it easy?

Any advise will be appreciated.

Thanks,
Larry

[John B.]

Firstly cutting the seat post and trying to hack saw it lengthwise
down the seat tub is going to be a pretty tedious project even if you
are successful.

I once drilled out a seat post using a "drill" I made from a hole saw
carefully ground down the fit the seat tube. It took me about a week
to make the drill and remove the seat post :-)

I would recommend reading Sheldon Brown's recommendations for stuck
seat posts. http://www.sheldonbrown.com/stuck-seatposts.html

My suggestion for an aluminum seat post in a steel frame would be to
us drain cleaner (lye, caustic soda, sodium hydroxide). Disassemble
the bike. seal the seat tube/seat post joint and pour drain cleaner
through the bottom bracket into the seat post.

Caustic soda (lye) is a very strong alkali and will burn you if it
contacts your skin and reacts with aluminum to produce hydrogen gas so
appropriate safety measures should be taken.
There a number of youtube films on this.
--
cheers,

John B.

[Sir Ridesalot]

At least the seatpost is turning and that gives hope of a fairly simple solution.

I've had great luck in removing the wheels and then strapping the nose and the rear of the saddle to a big table ie picnic table and then using the frame as the fulcrum to twist and pull the frame away from the seat. A lot of times the seatpost comes out of the seat tube very suddenly. You could tie the saddle to a fence or a tree; anthing as long as the saddle/seatpost is firmly fastened to something that won't move as you twist and pull on the frame. The frame gives a lot more leverage than twisting the saddle does.

Good luck and cheers

[Jeff Liebermann]

On Thu, 23 Jun 2016 19:20:41 -0700 (PDT), LF <fie...@gmail.com> wrote:

>With the seat post clamp undone, I can rotate the post left
>and right, using the saddle for leverage.

Good. That means you can use a slide hammer and puller to extract the
seat post. The trick will be getting a slide hammer with grippers
that are long enough to fit the length of the seat post. If
desperate, drill holes in the exposed part of the seat post to grap
the hooks at the ends of the "fingers":
<http://www.harborfreight.com/heavy-duty-slide-hammer-and-puller-set-16-pc-60327.html>
<http://www.harborfreight.com/slide-hammer-and-puller-set-14-pc-60554.html>
<https://www.google.com/search?q=slide+hammer+puller&tbm=isch>
Use lots of penetrating oil. If you have a walk in freezer, put the
frame in there for a while. The aluminum will shrink more than the
steel, thus enlarging the gap. If not, try dry ice.

If you don't want to go through all that trouble, hang the frame by
the saddle to an overhead beam. Have an accomplis push down on the
frame, so as to apply pulling tension on the seat post. Then, rotate
the saddle left and right as you did before while applying tension. It
might just pull out. The idea is that this derrangement can apply
more tension than you can just by pulling on the saddle while turning.


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[DATAKOLL MARINE RESEARCH]

Not

I have no idea why tube turns does not come out.

But you made a first error in pulling it out causing the turning but not out.

You jammed it. SEE jam in goo images. Gual, divided into 3 parts, tube post and your mistake in a another useful word.

The device is a propane torch. Heat tube gently 360 from bottom up till vapors rise from the junkture then pull straight out using gradual but regressive pulling

[DATAKOLL MARINE RESEARCH]

The imbecile software cut out as I was arguing with IT abt spelling.

Continue heating while pulling...Doahn stop heating.

The compound created by the ion transfer factory is not immediately dissolve blessed not even in a dish. In the tube, how would your fluid get at the compound ? On the designed slip fit the ion transfer added 2 atoms H and one biggie O billions if them !

Then a monkey cane up n yanked on the seat jamming it solid at the top.

Also exam for a mechanical problem eg a set screw on the side ...?

[AMuzi]

Since it moves, you'll likely get it out whole.

First wash out the ammonia with hot water from both ends,
spray dry. An oxide reducer can help but time is your enemy.

Rinse with solvent to remove any oils etc, spray dry then
try a good penetrant such as PC Blaster or Delco Penetrant.
Warming it with a heatgun then allowing it to cool can get
more of the residual moisture out before you shoot the
penetrant.

Tap the post and seat tube smartly[1] while applying your
penetrant, again from both ends. Mount the top of the post
in a vise horizontally and rotate the frame, pulling from
the BB end as you turn it. Assistant can tap the post and
shoot your penetrant in as you do this. If the top breaks
away, insert a steel bar inside the post and grab the stump
again in your vise.

If it all goes awry you can either machine it out (tedious)
or melt it out (paint loss).

[1] large smooth faced tool on the paint. A smart tap is not
a bash. You want vibration to help the penetrant, not dents
in the frame.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[AMuzi]

Good advice generally but you'll bend the saddle frame
before most posts move. A 24" adjustable wrench over the
post top is better than a saddle but we prefer post in vise
if it doesn't respond to moderate torque.

[DATAKOLL MARINE RESEARCH]

heat gun better than torch

lubricant before pulling ? wishful thinking but why not..

well....twisting is not in odor nor adding a dissolving lubricant.

twist gaul's the debris. the rotation piles debris packing into space you just expanded with the heat gun. PC would dislodge chunks of ionic debris further adding to the twisting pileup

pulling straight out seperates debris at worst n best remains as is in the expanded space.

hmmmmm turing the frame upside down, drill hole in BB, pour in penetrating oil, silicone lube, fix 2-3 ubolts to seat post with plate atop, heat n tap plate, get two tappers...balance the force.

if searched Japanese tool makers prob have a device for this op

drilling a 5/16ths hole in the BB too large for structural ? a good rod from McMasterCarr would fit down thru there.....

twisting from the frame .....a loser. place your bets with the can.

[Sir Ridesalot]

He said the post is moving side to side. I use my method because I don't have a vice on a bench and the bench secured to a floor. I haven't bent a saddle rail yet either. If the seatpost were not moving at all I wouldn't use a good saddle but I'd try it with a scrap one. I/ve had a few stuck seatpost suddenlt come loose and the out when using my method. I know you've had some really stuck posts where my method would not work. I hope that the OP's seatpost will come out easily.

Cheers

[Ian Field]

"DATAKOLL MARINE RESEARCH" <avag...@gmail.com> wrote in message
news:c9629f1a-7752-4424...@googlegroups.com...

If you can't twist it - use a slide hammer.

Car thieves used to make them up from surprisingly basic materials with a
self tapping screw welded on the end for pulling IGN lock barrels.

You need a long thin bar and a heavy lump of steel with a hole to fit the
bar. Weld a nut on the end of the bar so the lump can't fly off and devise
some way of attaching the other end to the seat post.

[DATAKOLL MARINE RESEARCH]

If you can't twist it - use a slide hammer.

https://goo.gl/6dFNtq

weight lifting plates with 2" holes ....

Goo sends a page

https://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.pces.uk.com%2Fmedia%2Fimg%2Fpipe-clamps%2Fcentromat-internal-type4_grid-11.jpg&imgrefurl=http%3A%2F%2Fwww.pces.uk.com%2Fproducts%2Fpipeline%2Fpipe-clamps%2Finternal-mechanical-alignment-clamps%2F&docid=7Ig1giW2vUtA9M&tbnid=IysIRQD7xobsEM%3A&w=640&h=380&bih=601&biw=1180&ved=0ahUKEwiX1q3gm8TNAhUDQiYKHR9nBhEQMwhiKAEwAQ&iact=mrc&uact=8

[DATAKOLL MARINE RESEARCH]

https://www.google.com/#q=aluminium+corrosion+removal

my potion for seat posts...

aluminum anti-seize mixed with a dollop of boiled linseed oil, flooding the anti sieze mass.

mix, spread over seat post n insert.

[DATAKOLL MARINE RESEARCH]

fluids discussion

I've used vinegar for SS knife rust. Knife in jar filled with AAA vinegar..vingar turns rust black...black rubs out with a rough ball of aluminum foil scrubber.


http://www.practicalmachinist.com/vb/general/electrolytic-corrosion-removal-assemblies-containing-different-metals-219301/