What's your formula for freeing off a VERY stuck seatpost?

[wheresthetorch]

Crude, but it did the job. Sometimes there's no alternative to using brute force.

Yeah, we had tried everything else - lubricants, coke, heat, sawing down the post. Then noticed a bulge in the seat tube - clearly the previous owner had rammed an oversize post into the frame!

 

[Drago]

My methods are...

Violence. Banging, shouting, calling down the Gods of Valhalla to smite thou seat post down with great vengeance and furious anger.

And when that doesn't work I break out the airsaw and a long blade and with a bit of care have even the most stubbornly stuck post out in a couple of minutes.

 

[rogerzilla]

The guy at Argos told me they melt out aluminium posts stuck in steel frames as a last resort. Braze melts at almost 300 deg C higher than aluminium (welded frames are even easier). Goodness knows what it does to the temper of the tubing, but they know what they're doing.

 

[Slick]

I've just realised that i have the same problem but as its a reasonably good bike i don't really want to risk damaging the frame by applying too much force or any heat at all. Only really leaves soaking in oil of some description, I'll need to get on it before it gets much worse.

 

[iluvmybike]

Ok then - how would Seatpost Man do it? (No doubt it is a trade secret!)

I would like to free my nice Ti seatpost from its Al framed captor, but only if it could be done without damaging either, which I suspect is not possible. Fortunately, my saddle height is acceptable as it is. I'd like to experiment with minor changes, but can get by without.

He will not tell you how he does it. but he gets them every time and never damages a frame and often not even the post. My business uses him when we have stuck ones - worth every penny

 

[dodgy]

Preventative maintenance is the answer, but you can't go back in time

Everyone, use today's crappy weather for good, take your post out and smear it with grease. Your future self will thank you.

 

[Crankarm]

What is the bike and a picture would be most useful? If it is an old jalopy, bin it and move on. Simply not worth wasting time and money on it.

 

[rafiki]

It's a Thorn Sterling and well worth bothering with.

 

[rogerzilla]

Dissolving an alu post out of a steel frame with caustic soda works but you need to be VERY careful of yourself and of the paint. It takes a few changes of fluid and a few days. You cut the post short first (to avoid wasting chemical dissolving stuff you don't need to) and plug it with the finger of a rubber glove stuffed with rag. Then pour your strong caustic soda in through the BB, taking care to rinse away the inevitable spillage as it bubbles. Change the solution after a day and keep going until it leaks at the bottom, by which point the post will be mere foil.

 

[Ajax Bay]

Dissolving an alu post out of a steel frame with caustic soda works

It's a steel seatpost in a steel frame.

The OP's exam question is a steel post in a steel frame (seat tube).

 

[rogerzilla]

I doubt the Thorn Sterling has a steel post.

 

[Ajax Bay]

My initial reaction was also to harbour some doubt (and restrained suggesting the magnet test), but remember being told: "Don't try and change the exam question." If it's an aluminium post, then the link to the 2015 thread I shared is apposite and @Yellow Saddle's 10 stage instructions I quoted above apply.

 

[ColinJ]

[QUOTE 5362485, member: 9609"]everytime a seat post thread appears I use it as a reminder to pull it out grease it up and push it back in - same with pedals they're another part that get themselves welded into place[/QUOTE]
Every time a seat post thread appeared I thought I should use it as a reminder to pull my titanium seat post out, grease it up, and push it back in ... Then I'd forget until the next time. And now it IS stuck!

 

[Slick]

Haha, I'm the same although maybe a bit worse as after checking the fleet, there is 2 stuck. I've just managed to free the titanium one but the steel is real and not budging. It is currently soaking in WD40 so battle will recommence later in the week.

 

[froze]

ok, you got a whole bunch of good advice, I didn't have time to read them all but I will say this: take all that advice and find the least destructive and least expensive method, in other words the easiest method, and do that first before jumping whole hog into a radical way, from the easiest least destructive you work your way up the ladder on rung at a time from easy to more difficult and more destructive, the most destructive should be the last thing you do.