A while back I encountered an impossibly stuck seatpost on an old Bianchi. I tried everything from a pipe wrench, to cutting the seatpost in half with a hacksaw blade from the inside out. All efforts failed miserably and added to my frustration. The only method I hadn't tried was pouring acid into the seat tube to dissolve to post. Although curious I was not willing to give it a try. Instead I designed and built my own seat tube extractor with parts from the hardware store for under $30. It worked flawlessly and saved hours of wrestling with the seat post. Once it was removed I could see why I had so much trouble. A previous owner had opted out of a seat post clamp and instead wrapped the seatpost in an inner tube and hammered it into the seat tube. Thanks a bunch...
What you'll need:
1. Steel pipe with a diameter slightly larger than the seat tube and longer than the seatpost
2. Threaded rod at least the length of the seat tube
3. 4 washers with the diameter equal to the seatpost diameter (These will need to fit inside the seat tube but not the seat post. I had to file mine down a bit to make them exact)
4. 1 or 2 heavy duty washers, larger in diameter than the steel pipe
5. A wood block with a hole drilled into it slightly larger than the seat tube diameter
6. 2 nuts to thread onto the threaded rod
What to do:
1. Remove the saddle completely
2. Remove crank arms and bottom bracket
3. Insert threaded rod into the seatpost and seat tube
4. Using the opening in the bottom bracket shell place the washers on the threaded rod and thread on one of the nuts.
5. Place the wood block over the top of the seat tube opening
6. Center the steel pipe over the hole in the wood block
7. Raise the threaded rod through the seat tube until the 4 washers come in contact with the seatpost
8. Place the larger washers over the rod and on top of the steel pipe
9. Thread the top nut into place on the rod
10. At this point everything should be arranged as the illustration above
11. Now tighten the top nut as the nut tightens the rod and seatpost will be forced up and out of the seat tube! (I had to hold the rod with vise grips to prevent it from rotating with the nut.)
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| The black stuff is the old inner tube |
What you'll need:
1. Steel pipe with a diameter slightly larger than the seat tube and longer than the seatpost
2. Threaded rod at least the length of the seat tube
3. 4 washers with the diameter equal to the seatpost diameter (These will need to fit inside the seat tube but not the seat post. I had to file mine down a bit to make them exact)
4. 1 or 2 heavy duty washers, larger in diameter than the steel pipe
5. A wood block with a hole drilled into it slightly larger than the seat tube diameter
6. 2 nuts to thread onto the threaded rod
What to do:
1. Remove the saddle completely
2. Remove crank arms and bottom bracket
3. Insert threaded rod into the seatpost and seat tube
4. Using the opening in the bottom bracket shell place the washers on the threaded rod and thread on one of the nuts.
5. Place the wood block over the top of the seat tube opening
6. Center the steel pipe over the hole in the wood block
7. Raise the threaded rod through the seat tube until the 4 washers come in contact with the seatpost
8. Place the larger washers over the rod and on top of the steel pipe
9. Thread the top nut into place on the rod
10. At this point everything should be arranged as the illustration above
11. Now tighten the top nut as the nut tightens the rod and seatpost will be forced up and out of the seat tube! (I had to hold the rod with vise grips to prevent it from rotating with the nut.)
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