Seized seatpost
 

I don't want to have to resort to using lye, I don't really have the space and resources for that. I've been periodically applying Sea Foam lube in hopes it eventually slowly penetrates, but I should probably use something a little stronger like PB blaster or something... It's just really strong smelling and I don't want to bother my neighbors.
Suggestions please! I know I can google it, but sometimes people here have some secret tricks up their sleeves.
https://cimg1.ibsrv.net/gimg/bikefor...612b093947.jpg

No secret tips from me, but from Park Tool: https://www.parktool.com/blog/repair...osts-and-stems

Patience and Penetrating oil. Kroil is great stuff.

Try to spread the clamp ever so slightly to help the penetrating oil get down there. If the BB out or it has bottle bosses, spray some in through them to work in the other direction. Pipe wrench on the post or put the post in a vise and try to break it free.

Cutting the seat post off and leaving enough to grab onto then running something like a carbide deburring bit on a long extension with a drill motor might remove enough material to let you split the tube and roll the edge to make it a smaller diameter than the seat tube it's in.

Seat post is a goner any way you look at it. Unless you want to lose the bike and save the seat post. Might be better to send both back to the scrap yard which sell scrap that eventually gets shipped overseas and made into new steel things. Not so much bikes anymore sadly.

But hey, I like a challenge too. So if you have to get it out, make it happen<grin>

It is a large club, lots of members have posted here before .. about that very thing..



note: where it says 'Archive' Below, and 'search threads' in the top right corner of the heading.. .

I had this problem with an aluminum seatpost in a steel frame where some corrosion at the bottom of the post causeD it to seize. The only thing that worked for me was brute force. I put a saddle I didn’t care about on the post and smacked the hell out of It with a hammer on the side of the nose to get it to turn. Once I got it to move back and forth a few times, I was able to wrench it back and forth by hand until it came free. The corrosion was only on the bottom inch of the post, which was plenty long, so I was able to cut the corroded section off and save the post.

RJ the Bike Guy has at least 7 youtubes on removing stuck seatposts. Some better than others. If I had one that would not budge I would use first his impact wrench method or second his saws-all method.

I don't know if this will work on seat posts, but this is a trick that works for frozen brake bleeders.
Cut the top off the seatpost. Use a propane torch to heat up the seat post thoroughly. This will heat up both the seat post and the frame. And then spray starting fluid into the seat post. This blast of starting fluid will rapidly cool down the seat post, and shrink it away from the frame.

I'm a reckless as the next guy but heat, and spraying starting fluid, into a confined area is probably not a good idea.

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1. By far the best penetrating oil is a mix you make yourself of 50/50 ATF and acetone. You don't need very much, but it's hard to buy either in small quantities.

2. At the auto parts store, you can also buy "Freeze Off", which has a coolant effect when you spray it similar to starting fluid. It's much less explosive, and has a penetrating oil component.

3. The suggestion to heat and cool the post through several cycles is a good one, and usually works. You can buy a MAPP gas torch at Home depot for maybe 20-30 bucks, and altlerlnate heating cooling cycles using that and Freeze Off, the Freeze Off is flammable, so first heat, playing the flame on the post, not the frame paint, then turn off the torch, put it over away from you somewhere, then spray with Freeze Off. Wait, then rinse and repeat a couple of times. I've never met a seat post that will not yield to this treatment.

4. I didn't even know you could still buy starter fluid. That stuff saved my life a couple of times in the dead of winter in MN. :)

Thanks, I've got some ATF lying around, ok have to get some acetone, and I'm definitely try the heating and cooling.

Can't resist chiming in on this. The stoker post on our tandem was stuck. I have access to liquid nitrogen....violà!
https://cimg9.ibsrv.net/gimg/bikefor...20f270beb2.jpg

You could try placing a bar into one of those seatpost holes with some leverage and twist. Too much and you might bend the frame or snap the seatpost but you could give that an honest effort first.

electric heat guns are cheap and if used properly won't destroy the paint.

I would try every non-destructive method available before destroying that post. It is a Miche Supertype. Look it up on the bay. Replacement is not inexpensive.

So is Permatex anti-seize recommended for seat posts? It can be a bit messy so could get on your clothes, but surely is superior at preventing seize over the long-term versus grease? What about rubbing some wax on it? That would be clean and tidy, or maybe just being careful to adjust the seat periodically.

Ohhhhh, nice. I was going to ask if it was a Miche. Those are pretty cool posts...

Dont get physical, you will just ruin something. If all else fails, Turn the bike upside down and remove the bottom bracket. Pour a mixture of ATF and acetone down the seat tube and let set over night. That should loosen the seat post.

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...just as a heads up about something else to be aware of: Sometimes, people buy or find a nice seat post that is just a little too large for the frame. They want to use it anyway, and they force it in. You can force it in, but not without a little bit of deformation to the seat tube (which you can usually spot as a bulge line on the outside). Those guys are much more difficult to extract, after they've been mounted for a while.

Hopefully, that is not your circumstance. If not, the heating/cooling along with ATF/acetone (both from the top of the post and the bottom, if you can do so) will eventually yield results and ought to preserve the post as well. I presume those posts are anodized, not painted.

I agree, it's not a good idea.

Stupidly, I do this with the tire on my wheel barrow frequently. I use propane from a torch and then the longest lighter I have. Works well in warm to hot days. However on cold days I have to be real quick or else the air inside the wheel cools off, contracts and pulls the bead back off the rim before I can get the air hose on it.

I should get a tube to put in the tire. But since I only use my wheel barrow two or three times a year, it is not something I think about till too late and I need the wheel barrow right now.

Those tires are so soft I use a rope in the middle with a piece of wood or steel twisting or a ratchet strap to hold the beads until I fill it. I have one like that too I should throw a tube in.

:rolleyes: That's just what I did on my older bike. I had that nice post around for a long time and last year decided again to try if I can put it in and I managed. I oiled it well but still didn't quite want to go in until I used light tapping to put it in. But when trying to take it out, I couldn't budge it. Luckily it is the height I can ride it, also don't think my legs will get any longer, unless maybe as you get older, your legs get shorter? :o

I didn't look at the 'several ways how to release stuck seat post' links but it might be worthwhile if you have some friendly car body shop around, to try on it the sliding weight hammer that is normally used to pull out body work that was bent in. I think some way to attach it to the seat post would be found, then you need one or two guys to hold the frame and third one to operate the hammer. Always easier to be at least two to work these things since the bike frame is not easy to clamp for this type of job.

Yes, came out nicely without any ill effect to the paint or frame. Sometimes it pays to be a scientist :)