roccobike

Well I picked up a Trek 560 along with several other bikes from a local guy. The Trek is in fair shape if a little small for me except the seat post is stuck solid in the seattube. The bike was left out in the elements so water probably went down the flutes in the seat post which I'm sure doesn't help. OK, I poured PB Blaster down the flutes (shown in the pic) a few times. I tried hitting that ratty seat with a 12OZ hammer on more than one occaision, nothing.
My next moves will be a little more drastic. I'm thinking of inverting the bike, removing the BB and spraying PB Blaster down the seat tube from the inside. If that doesn't work, I'm thinking either ammonia or Coca cola. Anyone agree with this or have other ideas? Recommendations welcome.
I'd hate to lose this nice bike due to this problem. I put the red tape on as a marker to let me know if the seatpost moved. BTW, the stem is OK so no problems there. Here are some pics:

ColonelJLloyd 

Do you have a bench vise? Did you see this video that Kurt posted recently?

auchencrow

^those would be the next things I'd try. (After that things start to get nasty.)

ronp6

I have had good luck using cold temperatures. I put dry ice on the seat tube. The aluminum seatpost contracts more than the steel frame and it is like pulling the sword from the stone. I have heard it works with just cold nights as well. I may have just been lucky with two of mine.

RavingManiac

Seeing you don't care about the seat, I would try a long pry bar between the seat rails and rotate being somewhat judicious wiith the force applied. Has the PB been applied at least over night?

auchencrow

Be careful not to use too much force or your stays will not stay.

roccobike

Thanks,
Yes I waited overnight, then several days re-applying PB. Good point auchencrow. I want to recover the bike. The saddle is junk anyway and the seatpost is expendable. Bending the stays is not what I want to do. The dry ice sounds interesting, but it's cold in my basement so I don't know if I can achieve the temp difference, but I may try anyway.
I've not seen that video before. If all else fails, that might be the way to go.
Tomorrow night I'm going to remove the BB and pour PB down the seat tube. I'll post here if I find a solution.
If anyone has another idea, please let me know.

Chombi

Cold+Penetrant = "Freeze-Off" by CRC. Worked for some (inclucing me) here already to remove stuck seaposts, stems and BB cups when PB blaster, Liquid Wrench, Kroil and other penetrants did not work. Just make sure you a bit of "Strategerie" when you use it to get best use of the temp differential/expansion/contraction effect.
Good luck, I hope you find a final solution for your Trek soon.
Forgot to note, Freeze-Off, per what I read on their spray cans, IS HIGHLY FLAMMABLE and should only be used in well venitlated areas. Closed up garages and pilot lights and other sparky things (uhmm.....static??) should be avoided when using it. I suspect like most other chemicals, it's also not good to breath into your system. I always fully opened up my garage door when I used it, so my house is still showing up in the latest Google Earth maps.......

Chombi

norskagent

Take it outside, put the seat in the crook of a tree (or equivalent), and twist the whole frame about the seatpost.

ColonelJLloyd 

Then, when you catch your neighbors staring yell, "Hey! What're you lookin' at!?"

BluesDaddy

Clamp the head of the post in a bench vise.

Chombi

OK,...........you can also tie down a small metal cage full of bannanas on to the doomed saddle and throw the frame into you local zoo's Gorilla exhibit (make sure they have an Alpha male silverback in the group) for a few minutes. pull out and check and repeat...and rinse.....as needed......

Chombi

jonwvara 

Maybe ftwelder will weigh in with photos of his amazing mega-leverage seatpost extractor. It was mentioned on another thread not so long ago. I actually saw it when I paid a visit to Frank's shop before Thanksgiving--it's a thing of beauty. I've actually thought about making one of my own--from wood rather than steel because I'm that's what I'm more set up to do, toolwise. To use it, you have to pull the bottom bracket, and the base of the seatpost has to be more strongly brazed to the bottom bracket shell than the seatpost is stuck to the inside of the seat tube, or the frame will be pulled apart. But I think you're more likely to pop the seatstays loose by trying to twist the seatpost loose with the ol' tree-crotch method (which I have admittedly used with success).

Frank! Frank! Are you out there?

Maddox

Dave Moulton, in an article on his awesome bike blog, recommends a method based on this idea (causing the aluminum to flex/shink through exposure to drastic temperature changes). I've been wanting to try it for awhile but haven't come across any severely seized stem/seatpost issues recently - knock on wood.

His method involves pouring a pan of boiling water on/down the seat post, and then letting it cool back to regular temperature. The expansion that takes place when the aluminum heats up followed by the concurrent shrinking when the heat is removed is usually enough to break the galvanic corrosion holding them together. The nice write-up on his blog is linked here.

norskagent

I would try the tree (or whatever) method up to a certain force point, also I would have a rear wheel (or hub) mounted for additional frame support.

noglider 

Keep us posted. You can do this. If you feel like giving up, we'll give you more advice and encouragement.

nlerner

+1. You'll then have the leverage of the frame, rather than struggling to move the post. It's also exciting to see those frame joints flex!

Neal

Maddox

I still need to know if Moulton's boiling water method works. It has the right combination of simplicity+believability to make me supremely curious. I'd almost like to come across a stuck seatpost, just to give it a whirl...

wrk101

+10 Put the seat or the top of the seat post clamp, in your favorite bench vise. I use the main frame triangle for leverage, turning it (hopefully) side to side. I am careful to avoid pulling on the back end of the frame (the stays), as I do not want to do damage there. My guess is that the larger main triangle tubes can take more abuse than the smaller stays. And the attachment of the seat stays in particular to the seat tube is pretty flimsy, compared to the top tube's attachment to the seat tube.

Oregon Southpaw

Maddox, going to try this right now. I've tried everything but the Freeze-off.

Chombi

You might try the boiling water method IN COMBINATION with Freeze-Off too, to get a maximum temp shift/expansion/comtraction. Kind of a super nuclear approach!

Chombi

GamleOle

https://www.classiclightweights.co.uk/seatpin-rest.html

noglider 

Goodness.

I'd prefer to use brute force. It's not as scary to me as caustic chemicals.

ColonelJLloyd 

I'm not afraid of chemicals, but I am a fan of brute force. Hulk smash!

Consider, Tom, that your mustache gives you powers of which the rest of us can only dream. The rest of us are often reliant on the crutches of "chemistry" and other "sciences".

FlatTop

I like to use the PB Blaster, as you've already done. It's more effective if you are willing to first put a tapered punch into the seatbolt ears and gently tweak them apart, opening the seat tube slightly and (hopefully) breaking the corrosion seal.

I know this is utterly barbaric, still it always seems to help.