Seized seatpost...VICTORY!

[Ajax Bay]

The Extreme Pressure additives provide boundary lubrication at the molecular level and are very effective at preventing metal-to-metal contact.

What, you mean like oil molecules don't provide "boundary" lubrication at the "molecular level"? What are these additives, or is that a secret? Perhaps they are 'oily' additives.

 

[SkipdiverJohn]

EP additives will prevent metal to metal contact in situations where the parts are being pressed together with sufficient force to disrupt a conventional oil film. Ultimately, they are more "oily" than plain oil. The difference in a bike seat post is going to be pretty marginal. In a vehicle final drive it might be the difference between seizing and not seizing.

 

[simongt]

If it's an alloy post in a steel frame

One of the great annoying misconceptions, of referring to 'alloy and steel'. Steel is also an alloy; of the element iron and various percentages of carbon and usually other elements, depending on what the steel is used for. I usually infer that folk are referring to aluminium alloy mix frames when they, as well as bike 'professionals' make the same error. The same marketing error is made with cars which have 'alloy rims'. Er, yeah, well steel is an alloy too - !

 

[SkipdiverJohn]

The thing is the correct phrase " if it's an aluminium alloy post in an iron alloy frame" doesn't exactly roll off the tongue so easily. You're completely correct though; steel is frequently referred to as though it was a pure element when it is not. The same crime is also committed for aluminium, where alloy parts are referred to as being made of the base metal, ignoring the fact they likely contain other alloying elements such as Magnesium. Pedantry rules!

 

[mjr]

It's ally, short for aluminium, not alloy.

 

[Deafie]

If it's an alloy post in a steel frame, alloy expands faster than steel so heating it wouldn't be very helpful. I guess once it has cooled down again the bond could be broken and it may come out easier then. Or if you have access to a large freezer...

Steel on steel should be easier to deal with. I'd remove the bottom bracket, plug the end of the seat post and invert the bike and pour some diesel into the seat tube and let it sit for a few days. I've never had a steel seatpost stuck but a good soaking in diesel had always worked for steel stems stuck in ancient roadsters.

My bike is steel with an aluminum seatpost and had been sitting outside 24/7 for a few years, tried wd40 and 3 in 1 with no luck so poured a kettle full of boiling water over the seat tube on an icy day and the post twisted out quite easilly. I think the speed of the heating is paramount

 

[biggs682]

@brucers i feel your pain

cutting a slot in the post is do able but fiddly and take care

what size o/d is the post as if close to 27.2 i have a special drill bit tool you can borrow

 

[brucers]

Perhaps try making a diy slide hammer? Some old metal, time and skill required?


View: https://www.youtube.com/watch?v=yCI9QoDOhzw

That sort of 'Skill' is something I don't have abundance!

 

[brucers]

If it's an alloy post in a steel frame, alloy expands faster than steel so heating it wouldn't be very helpful. I guess once it has cooled down again the bond could be broken and it may come out easier then. Or if you have access to a large freezer...

Steel on steel should be easier to deal with. I'd remove the bottom bracket, plug the end of the seat post and invert the bike and pour some diesel into the seat tube and let it sit for a few days. I've never had a steel seatpost stuck but a good soaking in diesel had always worked for steel stems stuck in ancient roadsters.

I'm not the sort of chap who can take out bottom brackets, knowing me I'd ruin something down there!

 

[brucers]

@brucers i feel your pain

cutting a slot in the post is do able but fiddly and take care

what size o/d is the post as if close to 27.2 i have a special drill bit tool you can borrow

Oddly enough no pain, I knew when I bought it, it was stuck. I'm almost resigned to hacksaw and files methods now as I worry about damaging the frame with too much twisting etc.

Thanks for the offer but I'll stick to whatever my shed has lurking in it to solve the problem. My drill is not up to much anyhow!

 

[mjr]

I'm not the sort of chap who can take out bottom brackets, knowing me I'd ruin something down there!

I'd say it's more likely to ruin something leaving it in place if you're going to try the chemical solutions. The main risk of damage when removing is if the non drive side cup has something other than the usual reverse thread. On bikes with old style non- cartridge BBs, that's the only one that needs removal and then the balls and shaft pull out through the left side.

 

[brucers]

I'd say it's more likely to ruin something leaving it in place if you're going to try the chemical solutions. The main risk of damage when removing is if the non drive side cup has something other than the usual reverse thread. On bikes with old style non- cartridge BBs, that's the only one that needs removal and then the balls and shaft pull out through the left side.

I agree so I'm stopping at wd40/85 and cola! I know some of the others may solve it but I'm erring on side caution. Next step is to cut of majority of seat post.

 

[brucers]

[QUOTE 5092406, member: 43827"]Be very careful. If It's steel in steel, apart from being laborious, there is a lot of danger of cutting the seatpost through and damaging the seat tube.[/QUOTE]
Laborious I can live with and it also sort of goes in hand with careful so hopefully I won't end up ruining the frame! Thanks anyhow.

 

[Ajax Bay]

Still haven't established whether the seat post is made of 'high %age Al alloy' or steel. Cutting a steel post will be a long old job and final success/result uncertain.

 

[davidphilips]

Still haven't established whether the seat post is made of 'high %age Al alloy' or steel. Cutting a steel post will be a long old job and final success/result uncertain.

A steel post may be hard to remove from a steel frame Ajax, but i would rather remove a alloy even a steel post from a steel frame than a jammed in carbon post in any type of frame or an alloy post in a carbon frame.