Bicycle Mechanics - AL seatpost in AL frame...won't budge..

just searched the forum, didn't find anything about...

brand new 27.2 Thomson Elite seatpost, aluminum, is partially inserted (approx 3-4 inches) into my brand new aluminum track frame.

it's a 410mm long seatpost, so, of course, it is not in the optimal position.

I used Pedro's grease on the inside of the seat tube, and a bit on the post itself before insertion.

It was a difficult install, but I figured I'd be able to get the post inserted deep enough. I was wrong.

My question is, therefore:

Will chemical solvents help, even though technically there is ZERO corrosion? Will some type of liquid wrench be better? I've used some lube/oil around the integrated seatpost collar to try and gain some lubriaction to no avail.

I've confirmed that the seatpost IS 27.2 and that my frame IS 27.2. Before I take it to my shop tomorrow, anyone have any advice? thanks..

If it is merely jammed, look for a product called Aero-kroil. We use it in the hangar all the time.

Get a friend to hold onto the frame while you hold onto the seat. Grab tightly and yank. Brace yourself for the inevitable fall.

Take the wheels off the frame.
turn the bike upside-down.
stand on the seat.
twist the frame while pulling upward.

If you use a shot of something that penetrates like GT85, you should be able to wiggle it back out no prob. I've used GT85 to get MANY seatposts out that were in too tight.

If you do use your saddle to torque the post, you should change it out for that cheap saddle that's sitting at the bottom of your parts pile. You don't want to bend the rails on that sparklin' new throne, do you?

I had an alu post pretty well seized in a steel frame once. Put on an old OEM saddle then slipped a steel cheater bar through the rails and twisted like a maniac. I actually pulled some muscles before the damn thing came loose...whew!

I had one kinda like that, but I had an old SR seatpost with a rectangle top. Dad and I took a big adjustible wrench and turned the post with the convenient flats.
Oh, we had a 6' pipe on it too. After soaking it. Al/steel corrosion sucks.

If you use a shot of something that penetrates like GT85, you should be able to wiggle it back out no prob. I've used GT85 to get MANY seatposts out that were in too tight.

Maybe my life is sheltered, but what is GT85 and where do you get it. I have not seen this product.
I am always open to new chemicals. Tks.

Not intending to steal the post but... a 27.2 seat post in a 27.2 seat tube and it gets stuck. Does this mean that I should opt for a 27.0 post in a 27.2 tube or maybe even smaller post???

Just recently unstuck AL seat/St frame.Friend's bike I had borrowed for Duathlon was not at right height for me.Since borrowed bike automatically =You will break something on it, I treated that bike like a newborn baby. Tried penetrating spray and seat twisting over 5 days,no go. Then read where someone used snow on bike forum.Aluminum shrinks and expands easily.So,wrapped the seat post with ice pack and warmed the frame tube with a hot wet towel.I took a large pipe wrench to the seat post with a 4 ft pipe.Voila!Landed on my butt in the garage,it loosened so easy. You may not want to use a pipe wrench because it will leave small grooves in the aluminum(I got permission from the owner first),but they can be sanded down. Also,be careful twisting seat post,read where a few frames have been twisted as well! Since you have no corrosion and the post is not in that far, you probably only need some good leverage such as the posting above with the adjustable wrench and long bar.Good luck.

PS
I broke his downtube shifter cable 2 days later.

Right on the pipe wrench, I dont even own one. Id be shot on site at the hangar if I did.
:(
The cold/hot method actually happened to me accidentally once. I had the original seatpost on my newly aquired(but old and neglected) Trek road bike. The post was at the right hieght so I wasnt too worried about not being able to move it. I took it indoors and outdoors several times that winter, and one night it was icy. THe steel frame apparently held its heat longer than the post, since the seat soon turned crooked when it broke the corrosion free. Lesson learned.

How far inserted is your post? In some frames the seat tube internally tapers, causing a wedging if its pushed in to forcefully.

brand new 27.2 Thomson Elite seatpost, aluminum, is partially inserted (approx 3-4 inches) into my brand new aluminum track frame.

it's a 410mm long seatpost, so, of course, it is not in the optimal position.




Why a 410mm seatpost in a track frame?

Just seems to be WAY too much post for any road or track frame. I second the guy above who said frames sometimes taper so the post might be wedged in.

Remember: If it doesn't go, force it!

PJ

I've confirmed that the seatpost IS 27.2 and that my frame IS 27.2. Before I take it to my shop tomorrow, anyone have any advice? thanks..

Is the frame 27.2 outside diameter or inside diameter? I figured I'd ask to be "safe".

Take off the wheels. Leave the frame and seat post outside overnight on a very cold night (colder than freezing if possible this time of year in GA). The cold should cause the aluminum to contract. Then, first thing in the morning, try the upside-town standing on the seat removal idea. If it still will not budge, heat up the seat tube with a small hand-held propane torch. Try not to burn the paint. The heat should cause the seat tube to expand. Then pull out the seat post.

Take off the wheels. Leave the frame and seat post outside overnight on a very cold night (colder than freezing if possible this time of year in GA). The cold should cause the aluminum to contract. Then, first thing in the morning, try the upside-town standing on the seat removal idea. If it still will not budge, heat up the seat tube with a small hand-held propane torch. Try not to burn the paint. The heat should cause the seat tube to expand. Then pull out the seat post.

Whoa...start with a hairdryer...

Whoa...start with a hairdryer...

sure...hairdryer first...but desperate times call for desperate measures...

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

thanks for the great info everyone..

27.2 is the internal size...so, I'm not using the wrong size stuff....

Tried the hair dryer/cold trick..didnt work...

Why a 410mm post in a track frame? I have long legs and kind of a shorter reach. So, my 250mm post doesn't work, and I got a good deal on the 410, and I can always cut...

After literally 3 hours of twisting, pulling, swearing, and twisting and swearing some more, me and my buddy, who's pretty damn buff, took turns wiggling that thing literally a mm at a time.

Thanks for all the solutions...a good thing to have in the searchable forums..

Turns out, there is some anomaly on the inside of the seat tube which is causing major obstruction.

Turns out, there is some anomaly on the inside of the seat tube which is causing major obstruction.

Not sure what frame it is that you have, but take it along to a framebuilder (or perhaps a really well equipped LBS) and get them to hone the seat tube for you. That should eliminate the obstruction, and you seatpole should be all slidey from then on!

Is it a soft anomaly, such as a butted/tapered tube? As is the case in my Cro-mo Giant frames. Or is it a true obstruction such as a bottle holder braze on? In either case I would much sooner chop a post than modify the frame.