I usually cut down my seatposts for the unicycles…being short tends to require me to do this quite often.
Usually I use a hacksaw and special guides that clamp on to the seatpost. That what my bike shop recommends. Their advice being…if you use a pipe cutter, be prepared to have the thing warp or flare out on you. Never use a pipe cutter to chop down a post.
Well, I got lazy and did just that today. After cutting my Cromo seat-post with a pipe cutter I filed it down. And then stuck it into my brand new KH36" frame.
It went in fine.
It doesn’t come out.
It’s completely lodged itself inthere. And the more I wiggle it, the tighter it gets.
I will try to remove it with a vice tomorrow. If not, then it’s consigned to the scrap heap
I’ve seen people use pipe cutters many times, but be careful. Filing it doesn’t necessarily correct the defect.
…but it’s really easy to cut a seatpost with a hacksaw… takes about a minute, or possibly two if you include the filing time, and hanging the saw up afterwards. What’s the problem?
Anyway, I hope you manage to get it out OK Ken. You must be able to extract it with a vice without damaging the frame even if you have to sacrifice the seatpost. If you give up and decide to scrap the frame, send it to me
I’ve also had a (aluminum) seat post get stuck after cutting. It took two people tugging at it to get it loose.
If you use a pipe cutter, make sure that any flaring is totally filed down. I did not have this problem with cutting a steel seatpost with a pipecutter, most likely because steel is less prone to flaring.
Angle grinders are relatively inexpensive and should leave a cleaner (no flare) cut. Be sure to wear safety glasses…tom
Don’t give up yet. If you are getting discouraged, take it toa bike shop, they deal with these problems every day.
If you are really wanting to give it a go, consider the different properties of the metal. An aluminum tube will expand with heat faster than a steel tube, so start by heating the seat post tube with a hair dryer or a heat gun (be careful). See if you can get some antisieze lubricant down the tube, even a little will help, so drip it on, then start wiggling.
I use a pipe cutter for my seat posts now. It does cause a little bit at the end flare out, but i spend about 5 minutes using a file to get rid of that little lip and then I grease it up and see how it goes in the frame, if it is too hard to get in then I file it some more. I have had no issues.
Hopefully you can get it out without damaging your KH 36
It’s worked perfectly well on steel and aluminium posts; it goes through the latter like butter. The only type left is carbon, and I’m (a) not likely to ever have one or (b) want to cut it with a normal hacksaw either!
i have had this problem, but from the frame warping at the bottom and/or bending … never the seatpost…
i never had a problem w/ my steel frames unless there was a little rust or something…
that said, last time i got my seatpost out of my DX it took a 3’ long 2x4 and a curb.
When I got my KH36. I was down at Bedfords picking it up, and when he was trimming the post for me, he used a pipe cutter, and it was very hard to get into the stem, actually we couldn’t get it to. But once we got some grease around the post it slipped in and out really nice.
If your going to use a pipe cutter, I recommend grease (not just some little spray lubricant, kinda like a gel, i’m not sure exactly what it’s called)
Only problem is you have to remember that the post is all greasy every time you take it out so that you don’t stain your clothes. You’re still bound to stain your hands. I may have to try that or file down my post now.
I think you might be onto something Ken (and others). You’ve got me wondering if I’ll ever be able to get the seatpost out of my KH36 again. I had trouble getting the seatpost into the frame following KH seatpost amputation via a pipe cutter. After much filing in went in without grease. I hope it’ll come out.