Another method for stuck, broken seatposts
03-15-20, 10:40 PM
#1
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Another method for stuck, broken seatposts
Some time ago I acquired this Ochsner for parts. The seatpost was seriously stuck and was also broken off just below the top of the seat lug. The previous owner had attempted to chisel it out, causing the seat tube to bulge slightly just below the lug. I determined the post fragment extended about eight inches into the tube. It was and aluminum post with a thin outer carbon fiber wrap. This Ochsner was constructed of Aelle tubing so the post OD should be about 26.6mm.
I briefly tried the axial saw cut technique. I became discouraged at how difficult and slow this process was. I thought if I could drill out most of the post first, cutting the remaining material out would be much quicker. So I got a step drill with a max diameter of 1" and an 8" extension. I drilled down a little at a time and shot some WD-40 (yes, I know, not a proper cutting fluid) between goes. It took about 15 minutes to cut the entire length of the post. I was pleasantly surprised to find that the remaining bits could be pushed to the BB shell (no need to saw) where I extract them with needle nose pliers. Another five minutes or so for that. The ID of the seat tube looks fine, so the step drill must have piloted on the post ID pretty well. Now I just need to file the lug ID a bit to clean up some of the chisel damage.
Someone else here on BF, I don't recall who, had tried this same thing and found the saw method was easier. Its another option at least.
I briefly tried the axial saw cut technique. I became discouraged at how difficult and slow this process was. I thought if I could drill out most of the post first, cutting the remaining material out would be much quicker. So I got a step drill with a max diameter of 1" and an 8" extension. I drilled down a little at a time and shot some WD-40 (yes, I know, not a proper cutting fluid) between goes. It took about 15 minutes to cut the entire length of the post. I was pleasantly surprised to find that the remaining bits could be pushed to the BB shell (no need to saw) where I extract them with needle nose pliers. Another five minutes or so for that. The ID of the seat tube looks fine, so the step drill must have piloted on the post ID pretty well. Now I just need to file the lug ID a bit to clean up some of the chisel damage.
Someone else here on BF, I don't recall who, had tried this same thing and found the saw method was easier. Its another option at least.
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03-15-20, 10:50 PM
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Very nice, I really like Unibits, I've never thought of using one to totally obliterate a stuck seatpost, but I will never forget it now!
03-16-20, 04:08 AM
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C&V drill to go with the theme of the forum.
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03-16-20, 05:51 AM
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Looks like another great solution! Thanks for that!
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03-16-20, 06:19 AM
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The other explanation might be that the AL is softer than the steel so the bit may have scratched the steel as it dug into the AL.
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03-16-20, 06:28 AM
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Thanks for posting this. I've never encountered a stuck seat post; however I'll add this to my list of potentially useful ideas.
03-17-20, 10:34 AM
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I am loathe to use a power tool to remove a stuck post or stem. One mistake and there goes the frame. On top of that, half of a hack saw blade and a half hour's time, and the post or stem is free and with almost no hazard to the thin tubing of the frame set. Anyway, this is how I Remove Stuck Posts or Stems.
Unless the stem or post is something special. Then I might spend a bit more time and a wayyyyy more caution and attempt to save the stem or post...
Unless the stem or post is something special. Then I might spend a bit more time and a wayyyyy more caution and attempt to save the stem or post...
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