roastbeef

i've got a 1985 bridgestone mb-1 with a seat post that's going absolutely no where. monkey wrench, hammer, monkey wrench and hammer, voodoo, witchcraft, none of it works. any suggestions?

dayvan cowboy

I remember one time a few years ago i was visiting a friend and was going to use his roommates bike and we couldn't get the seatpost to budge and he put some cooking oil on it and it worked. not sure if that helps.

cheg

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

But for god sakes don't steal the frame by seizing the seatpost.

TNCLR

Ammonia. And it's spelled "steel" for christ sakes.

kemmer

**** ammonia and cooking oil. When you're ready to get down to business buy some Aerokroil. If you can't find that, get some PB Blaster. WD 40 will probably work too, but the first two I meantioned are much better.

bbattle

If you use ammonia or lye, be sure to wash the aluminum seatpost thoroughly after getting it free. The two chemicals dissolve aluminum and over time will mess that seatpost up if you don't get the stuff off.

Hobartlemagne 

A seatpost is an inanimate object. It can't steal anything.

jgedwa

I had one that was locked in there solid. Amonia and time did not work. But I left it outside on a very cold day, and that did, amazingly.

jim

Steve90068

https://www.midwayusa.com/eproductpag...eitemid=188140

let it soak

fiataccompli

I bought a bike a few weeks ago that was being sold *cheap* for the same reason. I've bought the ammonia to try that. I used PB Blaster (a SERIOUS wonder product, btw) for a steel post stuck in a steel frame once & use it for all kinds of stuff, but I think the deal with the aluminum post & steel tube is a chemical reaction & the ammonia breaks it. I haven't tried the ammonia yet. I like the very cold day idea. I was also thinking dry ice would be good...or maybe discharging a paintball type C02 tank at the tube. The bike I picked up had been at one of the local bike shops where the mechanics basically gave up trying to free it.

Steev

How cold? I've got a quill stem that I haven't been able to budge by all the usual means and with winter coming I was going to try that.

jgedwa

Colder the better. Might not be a crazy idea to gently heat it up first to make the expansion/contraction differential as wide as possible.

However, when you are seriously considering this type of intervention with a seatpost you are really up against it. Get your hacksaw blades out and ready.

jim

delorean

Ammonia.

Freeze the post.

Pipe wrench.

That's what worked for me.

jpdesjar

don't let a post steal your frame man you just stand up for yourself

jet sanchEz

Be super careful, that frame is awesome. Worst case scenario----heat up the seat tube with a torch and the seat tube and post will expand but the aluminium post will shrink faster and pop out. Obviously, the paint will be toast but that frame is truly awesome, it is worth painting. I had to do this for my Ciocc, the post was so tight in there that when I was yanking on the pipe wrench, I nearly broke the seat tube.

jgedwa

+1 on being careful with an old MB-1. If you wreck it your soul will not fare well in the hereafter; St. Peterson will not let you through the pearly gates.

jim

roastbeef

yea sorry for the typo. i realize that 'steal' means to take what isn't yours and that 'steel' is an iron alloy. thanks for the responses. i'll post pictures when she's done.

Re-Cycle

Take out the bottom bracket, flip the frame upside down and pour whatever magic potion.. PB blaster, WD 40, penetrating oil etc that you choose down the seat tube. Then fix the seat post in a vice and use the frame's size for leverage and rock it back and forth. It'll come out.

Kotts

Not so amazing, really. Aluminum shrinks with cold (and expands with heat) more than steel. I had a friend whose seatpost tended to stick in the summer, but slip in the winter.

If nothing else works, go to your local ice cream shop and pick up some dry ice. Wear heavy gloves and pack it around the seat tube (or just lay the bike down with the seat tube on a chunk of it). Get things cold enough and it'll pop free.

Kotts

jgedwa

Yeah, but I was specifically amazed that the small temp difference of a cold winter day was enough to break it free.

jim

clink83

Galvanic corrosion:

Quote:

When two or more different sorts of metal come into contact in the presence of an electrolyte a galvanic couple is set up as different metals have different electrode potentials. The electrolyte provides a means for ion migration whereby metallic ions can move from the anode to the cathode. This leads to the anodic metal corroding more quickly than it otherwise would; the corrosion of the cathodic metal is ******ed even to the point of stopping. The presence of electrolyte and a conducting path between the metals may cause corrosion where otherwise neither metal alone would have corroded.

prawza

yeah, the aluminium acted as a sacrificial anode for the steel hence why it has seized up.

good luck with it lol..

roastbeef

i've been messing around with it for the past few days with still no luck. i was thinking about trying cut it out with a sawza, but if the two are bonded on a effing molecular level, is my only option really to just take a torch to it?

NotSoProjectPat

i got a post out of an old giant frame w/ a sawzall... i used a really long blade and just kinda did the dirty to the post w/ the blade going up and down and around pretty slowly and CAREFULLY and the post eventually just like crumbled inside... don't try to slice it up one side or you risk the frame

Ingleside

Have you tried this stuff? It works 9 out of 10 times.