Stuck seat post (aluminum).

[dvnjhn]

My Road bike has sat unused for about 7 years. I have tried to adjust the seat post, but it is stuck. I have used wD40 and tried heating the frame with boiling water. This allowed me to move it about 1/4 inch, but now it is jammed solid. No movement at all now. Any help or suggestions appreciated.

 

[cobbwheels]

I prefer to use fully synthetic motor oil 5w-30 or winter grade 0w-20 to unstuck metal parts.

It's nearly as penetrating as WD40 but far superior lubricant than WD40. You can probably make the synthetic oil even thinner by mixing it with mineral spirits to improve penetration and leave it overnight. WD40 will gel and become like a glue if you leave it for a long time that's why I never use WD40 anymore. So if you've used WD40, you'll probably need to use it again soon. It's like a bad drug giving you withdrawal and makes you want more.

If you have fully synthetic motor oil at hand, remove the seatpost clamp from the frame and apply the motor oil to the seat post. Leave it for several minutes and try to remove the stuck seatpost again. If it still won't budge then head over to the web and google the stuff.

Do note, a badly stuck seat post is likely to be bent so you might end up replacing the seatpost. Never ride with a bent aluminum seatpost even just a very slightly bent seatpost, it will snap eventually, ouch! So I suggest you "eyeball" the seat post at one end if you managed to remove it and see if it's even very sligthly bent, you should replace it asap.

Worst case scenario removal for me is to use a big, long monkey wrench to try to twist the seatpost off. This undoubtedly score and damage the seatpost, rendering it dangerous to use and needs to be replaced asap. But head over to the web first and see if others have better technique that won't damage the seatpost.

 

[Fourlegsgood2wheelsbad]

if OP lives in the states you could try penetrant oil spray with graphite. I forget the name .

 

[rovelo]

As CobbWheels said, don't ride with a bent Aluminium seatpost because unlike steel they fail (snap) with no warning.

If it is aluminium though it shouldn't rust. Is the bicycle frame steel? Put a few drops of heavy oil around the post and then use brute force. Turn the bicycle upside down and use a mallet if you have to - the saddle and post is replaceable! If it's bent anyway you might just have to bash it out anyway.

Other then that, the only other thing I can think of is using acetone to try and dissolve some of the rust. If you have a drainage hole near the bottom bracket you could also use that to get fluids in and around the post.

Good Luck!

 

[dvnjhn]

I have put machine oil on it like suggested. I can't budge it. So, I am leaving it soaking for a couple of days.

I got it about a quarter of an inch out yesterday, but its stuck solid now. Tried a mallet yesterday when it wouldn't move. Didn't make a difference. Thanks for the advise though.

 

[cobbwheels]

I have put machine oil on it like suggested. I can't budge it. So, I am leaving it soaking for a couple of days.

I got it about a quarter of an inch out yesterday, but its stuck solid now. Tried a mallet yesterday when it wouldn't move. Didn't make a difference. Thanks for the advise though.

If you don't mind scoring the seatpost and damaging it to the point you have to replace it, you can use a big, long monkey wrench to force it to twist. Apply oil if you managed to move it, even just a little.

The big long monkey wrench will give you more leverage and they're made for dealing with stuck pipes as well. Stuck seatpost is no different from a stuck pipe if it's round. If you can't find a big long monkey wrench, a smaller one will do and you can still increase leverage by putting a long pipe over the monkey wrench handle.

Using monkey wrench will most definitely score the seat post deeply and would render it unsafe to use.

But before you do that, google around first, there maybe less destructive means to remove a really stubborn stuck seatpost.