Stuck seatpost query (#987,673)

[torquer]

My Ritchey alloy seatpost on the Trek 5900 has gone from tight to frozen. Seat binder collar came loose with no problems, but nothing else is moving.

Recommendations?

[xjoex]

No big problem.

Take the bottom bracket out, put the bike upside down, squirt some liquid wrench down the seat tube. Let it sit a while.

Then with the bike still upside down stand on the seat and wiggle the frame back and forth, the post will break free.

-Joe

[Kervin]

+1, but in my shop days, we would just use Coke-a-cola. Less toxic (in a way), cheaper, and most people have some in the house. Sometimes you can get it in the seat tube via a waterbottle boss if you don't want to take the BB out.

[Clydesdale]

A few tips from the master...Sheldon Brown - stuck seatpost (http://www.sheldonbrown.com/stuck-seatposts.html)

[Peter P.]

I second Kervin's suggestion. Get the Coke down the seat tube and let sit for 24hours. I clamped the seatpost in a vise, considering it was doomed anyway, even if I got it unstuck, and used the frame for leverage. If it doesn't work on the first shot, let it soak for another 24hours.

Be sure and clean the seat tube out with a hone after you're done. If you can't get your hands on one, ask a local bike shop to do it.

[avalonracing]

This is really off topic but I had a cola this weekend with real cane sugar instead of High Fructose Corn Syrup. Trust me, the Coke with the HFCS should be saved for stuck seatposts only.

[torquer]

The feet-to-the-saddle trick has allowed me to turn the post (albeit with a horrific squealing noise), but no progress in removing the post.

I've applied various lubricants (but not through BB, since seat tube bottom is sealed), and maybe noise reduced a bit (or maybe I just got used to it) but still no progress outward.

I'd be willing to sacrifice the seat post, if necessary, but am very worried about using a hacksaw inside a carbon tube.

Anyone have any success with the rapid cooling of the post technique? What type CO cartridge? (I'm an old-school, frame-pump kind of guy, despite the carbon frame.)

Any other suggestions welcome, too.

[gone]

A few tips from the master...Sheldon Brown - stuck seatpost (http://www.sheldonbrown.com/stuck-seatposts.html)

I miss Sheldon.

[yarg]

I just removed a frozen thompson post from my legend. The only thing that worked was to put ice in a plastic baggy and hold it to the post. Aluminum has a much higher thermal expansion and contraction than titanium. A Trek 5900 I assume is carbon fiber, carbon fiber composites have a very low themal expansion rate so this trick should work very well in this instance also.

[CaptStash]

A few simple relatively low tech suggestions:

1) Try a product called "PB Blaster" which should be available through your local auto parts place. This stuff is far more effective than Liquid Wrench. Give it overnight to work.

2) You have the advantage of an alloy post in a carbon tube (right?). Rapid cooling would be the idea when you were trying to shrink the tube without shrinking the frame. Since carbon is relatively stable compared to alloy, slow colling will work just fine. You could arrange to leave the bike in your local grocer's freezer box (or if you live where it's really cold -- stick the bike outside overnight). Either way, you'll get significant shrinkage, which for once will be a good thing.

3) Since the damn thing does move, you can try turning while having your able assistant smack the underside of the seat with a rubber mallet to get it to start coming out. You should be able to "screw" it out with persistence and patience. Have you got an old really crappy seat you are willing to sacrifice? You could try a big pipe on the end of the seat to get more leverage, or even a monster pipe wrench in the pointy end of the seat itself (oh the horrors!).

4) If you are really bent on destroying the seatpost, I would put the biggest baddest pipe wrench you can get your hads on on the post, and do the unscrewing thing while simultaneously angling and pulling up to put pressure on the post to come out. More rubber malletting will surely help.

With all of the above, the hardest thing will be keeping the frame safe and stable and not messing it up. But that's what your able assistant is for right?

CaptStash....

[GuyGadois]

Dave Moulton (Fuso fame) has a trick to try: http://davesbikeblog.squarespace.com/discussion/post/584171

:beer:

-GG-

[dogdriver]

Anyone have any success with the rapid cooling of the post technique? What type CO cartridge? (I'm an old-school, frame-pump kind of guy, despite the carbon frame.)

Any other suggestions welcome, too.


Fire extinguisher (preferrably CO2, Halon is REALLY bad for you...).

Shoot the post for cooling and shrinkage. Probably more expensive than other methods, but how often do you get a chance to shoot a fire extinguisher?

[vqdriver]

Fire extinguisher (preferrably CO2, Halon is REALLY bad for you...).

Shoot the post for cooling and shrinkage. Probably more expensive than other methods, but how often do you get a chance to shoot a fire extinguisher?

:D +1 lemme do it.

[vqdriver]

This is really off topic but I had a cola this weekend with real cane sugar instead of High Fructose Corn Syrup. Trust me, the Coke with the HFCS should be saved for stuck seatposts only.
never heard of that. where do you get it?

[maunahaole]

Try a mexican grocery store for real sugar coca-cola. You want the made in Mexico stuff, NOT what is bottled here. While you are at it get a few flavors of Jarritos soda as well. I like the tamarind seed flavor.

[mister]

you sure the post is moving?

i had a post stuck and i turned it upside down and did the twist the whole frame thing.
turns out the seatpost was two pieces and the post wasn't turning in the seat tube but it was the clamp section turning in the seatpost.
i pulled the seatpost apart eventually...then used some vise grips on there to turn the post.
what a pain in the ass that was.

also, yes PBBlaster is way better then liquid wrench. try that stuff.

[Marcusaurelius]

yep---I second PB blaster. I used it once on a stem and a seat post and it worked like a charm. The stuff does smell awful and could be harmful to your health if you use too much indoors without ventilation. I just wonder if it might damage the carbon fiber?

[gomez308]

Go Kosher. You'll never go back.

never heard of that. where do you get it?

[torquer]

Hour and a half of rasslin' got the post out Saturday afternoon; my upper-body workout for the winter!

Tried the boiling water/quick cooling routine; bag of ice cubes at first (no fire extinguisher handy), but there was still enough snow on the ground to pack the post tightly, and this worked better. Twisting of the post generated heat all by itself after a while, so only needed to occasionaly apply the snow.

Post was greased its entire length, so I don't know what the problem was. Replacement carbon post dropped right in to the seat tube.

This was a real, Gitmo-level torture-test of an eight year old carbon Trek frame. Felt great on a 60-miler over winter-damaged roads Sunday, maybe even capable of tackling Paris-Roubaix (just don't use Georgie H's fork). I certainly looked the part, after three plus hours of snow-melt spray.

Thanks to everyone for the suggestions. This interweb thing might be usefull after all.

So now I have a dedicated crappy-weather bike, and can keep the Parlee nice and tidy, but I check out the weekend's race results and read that Z4s don't seem to do so badly in the snow, either:

http://www.velonews.com/article/87404/ben-day-wins-as-landis-returns-to-racing-at-the-snowy

[deechee]

wow, congratulations on being so persistent and patient! I probably would've started kicking the seat tube after about 5 minutes... (as if it would help)