So i have a old trek '84 and the SR seat post was seized in it badly. After soaking for a week (PB blaster etc) and applying heat to the post........and using a very large pipe wrench with cheater bar....it broke free. IT goes back and forth and pretty much all the way around now but it is still very very tight. I keep lubing and turn but the problem is i have nothing to apply outward/upward pressure as i am turning so it just sits there spinning in place. What can i use to apply upward pressure while turning without damaging the frame?
Just a tiny bit of upward pressure should slowly move this thing out but with as tight as the post is.....i need both hands and all my weight with the pipe wrench just to spin it so i can apply any pressure upward to inch the post up.
Put it in a vise?
If you're feeling daring, you can whack it downward to loosen it a bit more and then try to pull up.
How far down is the post? Can you grip it with the pipe wrench as close to the seatube as possible, angle the pipewrench upward so it's wedged against the post and then push up while rotating around to corkscrew it out?
Drill a big drain hole in the BB shell and tap it out from below?
People in this forum are not typical.
If you don't care about the post, drill a 1/2" hole thru it & use a large screwdriver or something to twist it back and forth while standing on frame to pry it upwards.
big screw driver/ hole wont work. The post is way too tight. It would snap the screw driver.
At this point the large pipe wrench with 2 foot cheater on ti turns it around but it takes alot of force to move it. Ive got PB and light oil down the seat tube and that helps a bit.
At this point i have the frame laying on the grass resting my body weight on it as it turn the post with the wrench. I couldnt care less about the post.
I think the post is about 2.5 inches in...maybe 3. ITs a SR Laprade post and it is clearly out far enough to see the full fluting and then some. Those posts are not very long at all and pretty much were around the same length.
I am surprised at how tight this thing is. I have cut them out before when siezed in frames. Its alot of work but it worked fine. IF i cant get this one to start moving up, maybe i will go that route. Not really the way i wanted to spend my day off but at least im not at work and it is somewhat nice out.
I have been trying to angle the pipe wrench and push upwards but i dont think it is moving up. I will get it eventually im sure.
Even in a bench vice i woudl be worried about bending the frame putting that much torque on it......its not loose enough yet for me to want to try it.
EDIT-- I just saw your recent post. It sounds like you have the right ideas. Good luck!
maybe as a last resort.
No, don't stand on the frame!
hold the frame, and have the seatpost fixed in place. Now you have leverage that's unlikely to damage the frame.
From Park Tool repair guides. This will mangle the seatpost.
Remove the saddle from the bike. Remove the wheels from the bike. Mount the bike upside down with the post clamped in the hard jaws of the vise. This will allow the frame to be used as a lever. It may be useful to have someone pull upward while you twist the frame side to side. If the post is very tight still, use care not use the rear dropout for leverage as this may bend the rear triangle.
If you don't have a vise on a sturdy workbench, perhaps you could use a junk saddle (from the LBS?). Set the bike upside down, but you want the handlebars off the ground. Maybe a raised platform would allow the saddle to be flat on the ground and the rest of the frame and bars off the ground? Then stand on the saddle and twist the frame while pulling it up.
I've use toe-straps to fasten a saddle, on a stuck seatpost, to a fence and then used the frame as the fulcrum to twist and apply pressure to pull the seatpost out. You could tie the saddle to a fence.
I'd be very wary about driving the seatpost in any further in case it got even more stuck.
Have you checked the seatube ears to be sure they're not pinched together enough to cause the seatppost to not come up?
I clamp the post in a vise with the frame out horizontally. Then I can twist the frame back and forth, while leaning back to apply tension and ease it out. If the post isn't frozen solid, this works 100% of the time with minimal effort.
Note: be sure to apply penetrating oil to the post (you can mix your own with oil thinned with 5 to 10 parts petroleum distillate, ie. OMS.
Also, friction will heat the working area considerably. Stop to rest and cool it often, because heat can act to freeze the post, then you'll have to saw it out.
An ounce of diagnosis is worth a pound of cure.
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Stick an old saddle you are willing to damage on it. Find an overhead beam, horizontal tree branch, etc, you get the idea. Lash the saddle to it, and literally hang from the frame, using your body weight to pull the frame down off that post. "Twisting in the wind" like a hanged convict helps. Yes it sounds ridiculous. I actually did this once, also due to one of those stupid fluted SR posts that let water in so easily. Who thought that putting multiple places for water intrusion was a good idea?
Seat post in frame. Tried heat( like hair drier) on the frame and liquid CO2, from say canned air on the seat post?
Another approach from a life-long sailor. Block and tackle. Pulleys. Or a winch. Tie the frame via the BB to one tree. Tie the seatpost clamp to one pulley and the other pulley to another tree. Tighten. Turn you lever to twist the seatpost. If you have enough tension, it will come out a little. re-tighten the pulley and repeat.
Is the seat post shot? Yes, clamp a vise grip or visegrip locking chain clamp to the post sideways and use an air hammer on the underside of the vise grip. Reset the vise grip on the other side, add more penetrating oil and air hammer again.
Last edited by grizzly59; 10-21-16 at 12:52 PM.
took most of the day but i got it. Frame saved. Lots of oil and brute force........using the turn in the same direction over and over and over and over 10000 times while twisting the pipe wrench/cheater bar combo. IM going to be sore tomorrow. IM glad i didnt have to saw it out. That is a pain as well and slow going.
Thanks for all the tips. That was one of the worse i have ever done.
I like it. Like "The Little Engine That Could" (that's a kid's story from way back); in other words - don't give up.