adam232

quite an old bike but the seat will not budge even though the bolt is loose, i have tried applying wd40 and a lot of force but to no use. If possible i would like to avoid hacksawing it out

demoncyclist

WD40 is useless in this instance. Try PB Blaster. Spray liberally- if you can remove the bottom bracket, turn the bike upside down and spray into the seat tube from that end. Let sit a few hours and spray again. Then see if you can move the seatpost.

adam232

thanks, and btw its a steel bike so I'm pretty sure that its rusted in, maybe something to dissolve rust would help?

Yo Spiff

I just had the same problem with an old MTB I picked up for $30. I sprayed penetrating oil (Liquid Wrench) onto the seatpost to seat tube joint, pried the bolt apart a bit and went pack periodically and whacked the seapost with a rubber mallet. Then I let it sit for a week so the oil could seep into the joint. After a week it came out using a large pair of vise grips to gain a bit of leverage.

Penetrating oil like liquid wrench is designed to loosen rusted and stuck parts. I also use it to clean old and rusty but recoverable chains. I remove the chain and put it in a ziploc bag with some penetrating oil for a few days. I wipe the Liquid Wrench off afterwards and apply a proper lube.

I always put a light coating of grease on the seatpost when installing them to try and prevent this.

Otter 718

I recently removed a stuck seatpost in a case where I wanted to keep the frame and seatpost both in good condition. I slotted a very large screwdriver through a hole in the seat clamp, and slid a two foot long pipe over the screwdriver. This gave me a lot of leverage to twist with, and pop it free.

demoncyclist

The PB Blaster will dissolve the rust. I've used it successfully on several occasions.

adam232

thanks guys il let it sit for a while now

mctrek

Adam, I'm dealing with the same thing right now. Trying to help out a friend who has a stuck Aluminum Seatpost (the kind that is just a tube, the saddle has a separate clamp that attaches saddle to seat post) in a Schwinn hybrid steel bike (newer China made Schwinns)... So far I have tried the following:

1) Soaked with Liquid wrench... Tap the seatpost and seat tube, used the saddle to try to twist seatpost
2) Removed bottom bracket... Applied Pepsi into seat tube. Let it sit for 20hrs, tried to twist free
3) Plugged the seatpost as far as the post goes. Applied heat via hairdryer to seat tube.... Then applied crushed ice inside tube... I think I will try this several times.
4) I'm soaking with Liquid wrench overnight again.

I am starting to see some movement in the seat tube. More side to side, not twisting yet... So I think I'm close. We'll see how it goes. Let me know how you do on yours. I don't want to cut the seatpost out yet... I think with some patience I'll get it out.

I want to try:
1) Pouring hot water through seat post and seat tube. Then plug and apply crushed ice and twist...
2) soak with Liquid wrench and add weight to bike to let gravity pull it out while having the seattube clamped in bike stand
3) Tap seat tube with sledge while holding 2x4 to get seat tube to move and then try to twist...

Found ideas on google... You can do search on "stuck seattube"...

temon00

Do whatever you can before you hacksaw. You will get 1/3 of the way through it, and think "dam, I shoulda tried that", but not be able to go back.

A few cycles of heat expansion might do the trick. I saw a guy in a video do that a few times, then put the post in a vice and use the whole frame as leverage.

Are you sure the seatpost isn't aluminum?

squirtdad

if it is aluminum post/ steel frame try the soaking in 10% ammonia.

also 50% atf and 50 acetene will loosen up a lot of stuff

freeze off is also really helpful

and a long lever to twist

here is a thread on my esperience in freeing a really stuck seatpost https://www.bikeforums.net/showthread...ory?highlight=

TornadoCAN99

I've had lots of success freeing stuck muffler sections of rust-belt winter driven cars using propane torch heat. If the frame & post are steel that could work here. If you decide it's time to trash the post, a LBS got one off a friends bike using a great big pipe wrench (~2-3 ft long) and cranking on the post...completely trashed it & bent the tube in, but it came out without wrecking the frame.

paul246

Use a propane torch or an electric heat gun on the outer tube and then twist the seat post out.

Apply the heat evenly on all sides of the tube from the top to at least halfway down.

squirtdad

You know you can build a frame with a propane torch, so you have to be super careful not to get it hot enough not to let the brazing flow and propane will almost for sure goof up the paint. This would be my last resort method

squirtdad

heres is bit of a repost on what it took to unstick a seat post:

After a long period of time, much searching of bike forums, consultations with friends and lbs, and several approaches I have succeeded in removing the seat post stuck in my gifted Torpado frame.

the bike had been sitting out side for at least a couple of years.

The seat post was shoved in as far down as it could go, there was no post at all above the clamp, just the head of the seat post.

First attempt, some PB Blaster and then a pipe wrench: no go

Next up: soak in 10% Ammonia. I turned the bike upside down and soaked for 3 weeks. Pipe wrench, no go. Cheater bar with 1 in pipe at the end: no go

try try again: Soak in 50/50 Acetone/ATF (automatic transmission fluid) This idea came from the forum and a PHD neighbor who runs a bike charity.....there is a lot of science behing this mix and test show it is better the PB blaster or Kroil. Pipe wrench: no go. Cheater bar no go.

OK so I need more leverage and a way to hold the head of the seat post firmly. Big ol vice? Don't have one, ok off to ACE and I came up with this using heavy steel staps and bolts



this grips strong. but still does not have enough leverage to move the post

so next step use Freeze-off (which seems to be really help..it is a penetrant and cold together, it will be my number one to try next time) and off to Ace again to add to the cheater bar, which resulted n this (note pic is after I had the post removed it was really stuck)



success, and looking at the post you can see the rust, corrosion all over



Overall lesson, lots of time, big lever and check out Freeze-off

rithem

I clamped the head of the seatpost in my 6" workbench vice and used the frame as leverage managed to get it out. Super loud and the seat tube got pretty hot. thankfully I didn't damage the frame. I didn't care about it that much so I was willing to take risk, but on a "nice" bike I may have been a little less persuasive. I used liquid wrench soak from top and bottom through the BB shell. but using something that could rapidly chill the seatpost inside the hot/warm seatube could give you a small window to get it out, but you would need to move fast

BikeRider22

Sheldon Brown had a great article on this very subject.
If you don't mind, I'll let you search for it.

mctrek

Squirtdad... Thanks for the input... I'll try the amonia and the 50/50 mixture... Did you pour this mixture from the bottom bracket with a plug in the tube? Did you protect the paint when you did this?
So far no go... Also could you send some pictures of the "jig" you made to clamp the seat post? That looks pretty sweet and I might try to make something similar to it if you show me how it actually clamps to the seatpost. Mine is just the round tube, with the top being smaller in diameter than the main tube.

squirtdad

I just poured in from bottom bracket holes (BB removed) the seatpost it self did all the pluging (campy post, not the simple ones with an open tube end). Look at my post #14 and you should see pics of how I clamped to the seat post again the seatpost had a forged head so I took heavy metal straps and bolted them on....the forged head gave the steel some thing to leverage against. you mighe be ample to do similar by drilling a hole through the seat post and running a bolt through it. then the straps would have something to clamp against.

mctrek

Finally got it out. I used the CRC Freeze-Off on mine! That stuff is awesome! I poured hot water in the seat tube then I sprayed with freeze-off! Repeated several times and then I saw that the seat post actually moved a tiny bit. Let it soak another hour, then tried it again and it came out! For a clamp I used an old UNO mountain bike stem. The seat post was 28.6mm which is close enough to 1-1/8" diameter. So I mounted the stem on the seat tube and in the other end of the stem I mounted a long steel tube. Squirtdad, thank you for letting me know about Freeze-Off, that stuff worked much better than WD40, Liquidwrench, PB-Blaster, Pepsi, hot water-ice, etc. The only thing you have to be carefull with is that it has a strong smell. I used it in my basement with all the windows open and if I were to do it again I would use it outside.

BikeRider22

That's a lot of leverage!

Which way did you torque the lever?
So that the seat post spun inside the seat tube?

Thanks a lot!




[QUOTE=squirtdad;14591351]heres is bit of a repost on what it took to unstick a seat post:

After a long period of time, much searching of bike forums, consultations with friends and lbs, and several approaches I have succeeded in removing the seat post stuck in my gifted Torpado frame.

squirtdad

[QUOTE=BikeRider22;16389039]That's a lot of leverage!

Which way did you torque the lever?
So that the seat post spun inside the seat tube?

Thanks a lot!




that is correct, I used the lever to spin the seat post inside the seat tube. Once the seat post broke loose it take that much lever to finish removing it.

fietsbob

Further evidence there needs to be a Stuck seatpost Stickie on this Forum ..

SJX426 

I was successful in using Kroil. Freeze Off would be a good choice as well. I happened to use a torch on the post prior to removal. The key is breaking the bond between the two materials. The next challenge is overcoming all the crude that interferes with the sliding action.

During one of my consulting gigs, we had to mount a bearing on a shaft where the ID and OD were the same. Tolerance prevented the two from being assembled. We stuck the smaller of the two in the freezer overnight and it just slid right on. Using Freeze Off is the equivalent and most likely the most effective. It is important to include some kind of lubricant in the process. Kroil is very effective in penetrating over time. The 4Wheel crowd us PB Blaster on rusted suspension bolts by letting them soak for a week or so. Heat helps too.

Duane Behrens

auldmagoo

I have used an industrial heat gun (similar to a hair dryer, but with attitude) and a CO2 fire extinguisher. Heat the frame with the heat gun for a few moments, then fire the contents of the extinguisher down the seat post while twisting it. Has worked every time for us.