Stuck seat post
#1
Senior Member
Thread Starter
Join Date: Jun 2010
Location: South Suburbs
Posts: 52
Bikes: Leader 735TT mishmash of everything
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Stuck seat post
I got a frame from a very confused friend that is a 27.0 seat post size, and there is a 27.2 THOMSON seat post in it. It's stuck in at least 4-5".
Is there a way to salvage either the frame or seat post....or both? I'm still flustered at how some kind of man would manage that.
And YES. I'm sure it's a 27.2 in a 27.0. I have the specs on the bike and the numbers on the seat post confirmed that it was a 27.2. (along with my micrometer)
I'm guessing a propane torch or something to the like.
Edit: and I'm upset that it's a thomson and not a no name post.
Is there a way to salvage either the frame or seat post....or both? I'm still flustered at how some kind of man would manage that.
And YES. I'm sure it's a 27.2 in a 27.0. I have the specs on the bike and the numbers on the seat post confirmed that it was a 27.2. (along with my micrometer)
I'm guessing a propane torch or something to the like.
Edit: and I'm upset that it's a thomson and not a no name post.
#2
Senior Member
Join Date: Sep 2007
Location: Vancouver
Posts: 1,438
Bikes: NOYB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
If the post is physically rammed in there rather than just oxidized, there's not much you can do besides applying brute force.
Frankly, I don't see how it could get that far into the frame in the first place if it's a size too large.
Frankly, I don't see how it could get that far into the frame in the first place if it's a size too large.
#3
I'm Carbon Curious
Join Date: Aug 2005
Posts: 2,194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Put an old seat that you don't care about on the seatpost. Put penetrating oil like 3-in-1 oil in between the seatpost and the seattube. Then get a hammer and bang at the ends (nose or the back of the saddle) from side to side. If it moves, try pulling the seatpost out. Little by little repeat these steps. If it doesn't move, then put more oil in and let it sit overnight. Go back the next day and try again. Hope this helps.
#5
Senior Member
Join Date: Jul 2010
Location: West Coast
Posts: 551
Bikes: Centurion Ironman Expert, Bianchi Sport SX, SR Pro Racing, Vitus 979, Cannondale mountain bike, Schwinn Prologue TT Bike, Litespeed Tuscany, Principia Rex Pro (frame broke), Rossin (model unknown), Litespeed Classic, Schwinn prelude
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
could you maybe flip the bike upside down(like your working on it), stand on the seat and pull up on the seat tube?
#6
Senior Member
Join Date: Jul 2010
Location: West Coast
Posts: 551
Bikes: Centurion Ironman Expert, Bianchi Sport SX, SR Pro Racing, Vitus 979, Cannondale mountain bike, Schwinn Prologue TT Bike, Litespeed Tuscany, Principia Rex Pro (frame broke), Rossin (model unknown), Litespeed Classic, Schwinn prelude
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
that sould give you a lot of pulling power, never had to try it, but in my mind it would work
#8
17yrold in 64yrold body
Join Date: May 2010
Location: Northern CA
Posts: 922
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
+1 Grand Bois. Aluminum has a higher coeficient of expansion than steel, so heating it will make it tighter. If you have a vise mounted to something SOLID, you could carefully tighten the vise on the straight sides of the seat post (bike upside down), and use the bike for leverage--while lifting the frame, twist it slightly, and work the post out.
#9
Banned.
Join Date: Jul 2010
Posts: 2,325
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
If the above methods don't work, you could rig up a hydraulic press with a couple of car jacks and some pieces of 2x4 to slowly press the seat post out. You do have to be careful, since this method is able to exert enough force to break welds on the bike frame, but if they give first, I'm not sure the post would have been removable by any other method. You also need to be careful to use the same amount of force on both sides of the bike to avoid bending frame/post.
#10
Senior Member
Join Date: Jul 2010
Location: West Coast
Posts: 551
Bikes: Centurion Ironman Expert, Bianchi Sport SX, SR Pro Racing, Vitus 979, Cannondale mountain bike, Schwinn Prologue TT Bike, Litespeed Tuscany, Principia Rex Pro (frame broke), Rossin (model unknown), Litespeed Classic, Schwinn prelude
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
well if the seat height is ok for you dont mess with it haha, and as a +, nobody could steal your seat!
#11
Guest
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
I'm with chadwebster. I had this exact same problem once. I removed the BB, shot a bunch of penetrating oil down (up?) the seat tube, let it sit overnight upside down. The next morning I mounted an old seat, stood on the seat (with the frame upside down, again), and twisted the frame. Came out no problem.
#12
Senior Member
Please don't use unpadded vise jaws on anything you want to keep. There is just no way to avoid badly scarring the surfaces of the metal at the best of times let alone in a case like this where you need to use a LOT of force.
#13
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,779
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 907 Post(s)
Liked 365 Times
in
267 Posts
If the above methods don't work, you could rig up a hydraulic press with a couple of car jacks and some pieces of 2x4 to slowly press the seat post out. You do have to be careful, since this method is able to exert enough force to break welds on the bike frame, but if they give first, I'm not sure the post would have been removable by any other method. You also need to be careful to use the same amount of force on both sides of the bike to avoid bending frame/post.
I would try the upside down -- stand on the seat -- twist the frame method. If that doesn't work, you're probably left with cutting off the post an inch above the frame and 'carefully' sawing a slot down the inside of the post. Then grab an end with pliers and twist it inward to break it loose. It's tricky to do.
#14
Senior Member
Thread Starter
Join Date: Jun 2010
Location: South Suburbs
Posts: 52
Bikes: Leader 735TT mishmash of everything
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I'm going to use penetrating oil and invert the frame to try pulling it out. Then if that doesn't work, I think I'm going to cut the seatpost at the end of the tube and find a very long jigsaw bit and cut long slots down the seatpost pretty much like what rm-rf suggested.
#15
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
This is what Sheldon Brown suggests:
https://www.sheldonbrown.com/stuck-seatposts.html
Btw, you might want ti read this -
https://road.cc/content/forum/14720-s...st-stuck-frame
A friend of mine who took a bike with a stuck seatpost into a bike shop in Cambridge was told by the owner that he wouldn't touch it, since he knew someone who had died attempting to remove a stuck seatpost!
A friend of mine who took a bike with a stuck seatpost into a bike shop in Cambridge was told by the owner that he wouldn't touch it, since he knew someone who had died attempting to remove a stuck seatpost!
Last edited by meanwhile; 07-24-10 at 12:22 PM.
#16
Senior Member
Thread Starter
Join Date: Jun 2010
Location: South Suburbs
Posts: 52
Bikes: Leader 735TT mishmash of everything
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Oh it's okay I'll have a will written up shortly before I attempt this... 
So the frame is Aluminum...and the seat post is aluminum....so If my thoughts are correct, heating won't do much good?

So the frame is Aluminum...and the seat post is aluminum....so If my thoughts are correct, heating won't do much good?
#17
Senior Member
Join Date: Jan 2004
Location: Madison, WI USA
Posts: 6,676
Mentioned: 48 Post(s)
Tagged: 0 Thread(s)
Quoted: 2267 Post(s)
Liked 1,578 Times
in
1,093 Posts
What if you applied some serious cold to the post, then gentle (like, hair-dryer or low-setting heat gun) heat to the tube? _Might_ help make whatever above method you choose more effective.
Seems like the rotate-and-pull method has the most promise.
With the bottom bracket out, is the bb shell "open" where the bottom of the seat tube meets it? If so, you could drizzle more oil into the tube that way.
Seems like the rotate-and-pull method has the most promise.
With the bottom bracket out, is the bb shell "open" where the bottom of the seat tube meets it? If so, you could drizzle more oil into the tube that way.
#18
Thrifty Bill
Join Date: Jan 2008
Location: Mountains of Western NC
Posts: 23,538
Bikes: 86 Katakura Silk, 87 Prologue X2, 88 Cimarron LE, 1975 Sekai 4000 Professional, 73 Paramount, plus more
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1226 Post(s)
Liked 928 Times
in
608 Posts
I am able to get most stuck posts out via using PB Blaster. I let it soak for a day or two. I install a junker seat on it, put the seat in my bench vise, and carefully rotate the frame. Note, you can damage the frame doing this, so be careful.
Out of a dozen stuck posts, this has worked 11 times. The 12th time is going to require cutting out the post.
I just removed one yesterday using the PB Blaster/bench vise method.
Note, this is with alloy posts in steel frames.
Out of a dozen stuck posts, this has worked 11 times. The 12th time is going to require cutting out the post.
I just removed one yesterday using the PB Blaster/bench vise method.
Note, this is with alloy posts in steel frames.
#19
Senior Member
Thread Starter
Join Date: Jun 2010
Location: South Suburbs
Posts: 52
Bikes: Leader 735TT mishmash of everything
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Status: sitting in my garage soaking in my mystery penetrating oil. Seriously. It has gotten so many bolts off of my rusty car and it doesn't even have a label...<3<3
Trying to get it off tomorrow. Although I have a vise, I don't have an old seat. I get rid of the parts I don't use. I know, shame on me.
Trying to get it off tomorrow. Although I have a vise, I don't have an old seat. I get rid of the parts I don't use. I know, shame on me.
#20
Senior Member
If you MUST use the vise to hold the seat post then the best possible way to do it is to drill a hole in a scrap block of 2x4 that is a very close fit to the seat post. Then cut it along the axis of the hole so you have a set of saddle blocks to best grip the seat post when you clamp it all up in the vise. If this means riding your spare bike.... you DO have a spare bike, right?... to the hardware store to get a suitable size spade drill bit for wood that is fine. With jobs such as this the key is prep and more prep before the final deed is done so you avoid damage to expensive parts.
#21
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,779
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 907 Post(s)
Liked 365 Times
in
267 Posts
Status: sitting in my garage soaking in my mystery penetrating oil. Seriously. It has gotten so many bolts off of my rusty car and it doesn't even have a label...<3<3
Trying to get it off tomorrow. Although I have a vise, I don't have an old seat. I get rid of the parts I don't use. I know, shame on me.
Trying to get it off tomorrow. Although I have a vise, I don't have an old seat. I get rid of the parts I don't use. I know, shame on me.