How would you get this seatpost removed?
03-22-23, 12:13 PM
#26
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Originally Posted by dddd
Folks, this is 2023, and stuck posts aren't the nightmare that they used to be.
Muriatic acid dissolves aluminum.
Alkali solutions embrittle steel.
Some of us have found that cutting off 1" above the opening and using a slender, sharp sawzall blade can get any stuck alloy post out fast, with no damage to the frame.
The tricks are:
1) Begin by probing with a bent spoke to determine the inserted length of the post.
2) Make certain (by means of probing with a sharpened bent spoke) that the slot in the post is cut through to the steel all the way to the bottom of the post.
3) Do not align/clock the cut with the slot in the lug.
4) Do not let the blade contact the edge at the lug opening, so keep the blade's cutting side tilted slightly at all times.
5) Make sure that the end of the blade can't/doesn't reciprocate/travel too high and thus "catch" above the upper end edge of the seat tube, remembering that the directional teeth will tend to try to push the saw and blade upward as the blade digs into the aluminum and reciprocates through it's perhaps 1" of stroke.
6) The cut height doesn't need to extend much above the height of bottom of the slot in the seat tube, and doesn't need to extend to the end of the seat tube.
Please read the above (5) instructions several times, slowly.
Be patient and controlled with the cutting, especially when starting out, and again when extending the cut to just barely above the height of the lower end of the slot in the frame's seat tube.
If the teeth out near the tip of the blade clog, or seem to become dull, they can be directionally sharpened using a Dremel "wafer" disc using good technique. The leading teeth should do all of the cutting. Cutting oil on the teeth recommended, any oil will do.
Once cut through to steel, the post can be easily twisted out. For heavier amounts of twisting force using plumbing pliers, put a reinforcing insert such as a dowel into the ID of the end of the post. Back-and-forth action and WD40 should make this easy.
I've had to "slenderize" a Sawzall blade on the bench grinder to cope with the narrow ID of the post.
I've had to sharpen the teeth at the tip of a used blade.
There is no tendency for the blade to dig into the steel, unless you let the teeth contact the edge at the opening or at the slot.
It takes a lot of concentrated pressure to get a Sawzall blade's teeth to even start digging into steel, which is pretty much impossible to achieve at the tip of the blade.
Muriatic acid dissolves aluminum.
Alkali solutions embrittle steel.
Some of us have found that cutting off 1" above the opening and using a slender, sharp sawzall blade can get any stuck alloy post out fast, with no damage to the frame.
The tricks are:
1) Begin by probing with a bent spoke to determine the inserted length of the post.
2) Make certain (by means of probing with a sharpened bent spoke) that the slot in the post is cut through to the steel all the way to the bottom of the post.
3) Do not align/clock the cut with the slot in the lug.
4) Do not let the blade contact the edge at the lug opening, so keep the blade's cutting side tilted slightly at all times.
5) Make sure that the end of the blade can't/doesn't reciprocate/travel too high and thus "catch" above the upper end edge of the seat tube, remembering that the directional teeth will tend to try to push the saw and blade upward as the blade digs into the aluminum and reciprocates through it's perhaps 1" of stroke.
6) The cut height doesn't need to extend much above the height of bottom of the slot in the seat tube, and doesn't need to extend to the end of the seat tube.
Please read the above (5) instructions several times, slowly.
Be patient and controlled with the cutting, especially when starting out, and again when extending the cut to just barely above the height of the lower end of the slot in the frame's seat tube.
If the teeth out near the tip of the blade clog, or seem to become dull, they can be directionally sharpened using a Dremel "wafer" disc using good technique. The leading teeth should do all of the cutting. Cutting oil on the teeth recommended, any oil will do.
Once cut through to steel, the post can be easily twisted out. For heavier amounts of twisting force using plumbing pliers, put a reinforcing insert such as a dowel into the ID of the end of the post. Back-and-forth action and WD40 should make this easy.
I've had to "slenderize" a Sawzall blade on the bench grinder to cope with the narrow ID of the post.
I've had to sharpen the teeth at the tip of a used blade.
There is no tendency for the blade to dig into the steel, unless you let the teeth contact the edge at the opening or at the slot.
It takes a lot of concentrated pressure to get a Sawzall blade's teeth to even start digging into steel, which is pretty much impossible to achieve at the tip of the blade.
I'd add only that if you have any trepidation about using a Sawzall (or knock-off) consider what I use, sometimes: Stanley make a comfortable handle you can screw in any brand of "reciprocating saw" blade and do all the tedious work by hand!
It's not fast but has a lot more control and less chance of a novice going too far too quick! Bitter experience teaches: you can't put that metal back (not easily) once it's gone.
As dddd says, you often have to modify those blades to make them narrow enough for a seat post.
And I still have nightmares about some of those ridiculous struggles with "welded in" posts (and stems) of the past...
03-23-23, 06:00 PM
#27
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I have tried several methods to loosen things stuck on a bicycle frame. Some of the methods work some of the time.
Last year I watched a You-Tube video and saw the most successful method that I have seen.
Heat gun. Used for stripping paint and many other things. Available at hardware stores for about $50 US.
I have used the heat gun for seat posts, seized bolts, pedals stuck in cranks. I usually apply penetrating oil the day before. This has saved me lots of time and has less risk than some other methods.
I am surprised that no one else has seen this on You-tube.
Last year I watched a You-Tube video and saw the most successful method that I have seen.
Heat gun. Used for stripping paint and many other things. Available at hardware stores for about $50 US.
I have used the heat gun for seat posts, seized bolts, pedals stuck in cranks. I usually apply penetrating oil the day before. This has saved me lots of time and has less risk than some other methods.
I am surprised that no one else has seen this on You-tube.
03-23-23, 06:20 PM
#28
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Originally Posted by Hummer
I have tried several methods to loosen things stuck on a bicycle frame. Some of the methods work some of the time.
Last year I watched a You-Tube video and saw the most successful method that I have seen.
Heat gun. Used for stripping paint and many other things. Available at hardware stores for about $50 US.
I have used the heat gun for seat posts, seized bolts, pedals stuck in cranks. I usually apply penetrating oil the day before. This has saved me lots of time and has less risk than some other methods.
I am surprised that no one else has seen this on You-tube.
Last year I watched a You-Tube video and saw the most successful method that I have seen.
Heat gun. Used for stripping paint and many other things. Available at hardware stores for about $50 US.
I have used the heat gun for seat posts, seized bolts, pedals stuck in cranks. I usually apply penetrating oil the day before. This has saved me lots of time and has less risk than some other methods.
I am surprised that no one else has seen this on You-tube.
Penetrant applied as the post cools is likely to be better drawn in, especially where the bond has broken between the tube and the post. I've used this method on a few quill stems, which twisted out with relative ease after everything cooled fully.
I don't know how much heat it would take to degrade the paint or decals on the seat tube, but a heated stem doesn't seem to get the headtube all that hot the way that heat will travel between a post and a seat tube.
03-23-23, 06:29 PM
#29
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Couldn't edit my above post to add the following:
Even without the differential thermal expansion, heat really softens the bonds of stuck metal parts like steel/steel cotter/cranks, allows cotter removal without bending the precious cotter.
Even without the differential thermal expansion, heat really softens the bonds of stuck metal parts like steel/steel cotter/cranks, allows cotter removal without bending the precious cotter.
03-23-23, 09:43 PM
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the heat guns I own are H-O-T ! Even those with a "low" setting are significantly hotter than say a hairdryer on "high".
One thing they are made for is to remove paint, and they do, will scorch wood too so you have to develop the feel for where the limits are and be watchful.
One thing they are made for is to remove paint, and they do, will scorch wood too so you have to develop the feel for where the limits are and be watchful.
03-23-23, 11:01 PM
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After a good soak in PB-Blaster then use the freeze technique. Look it up on youtube. Freezing just might do the trick. You can use a brand name like Freeze Off ot just get a few cans of Air used for blowing out the grit on key boards. Just hold the can upside down to get the freezing liquid out (Usually Trifloro Ethane like).
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03-24-23, 07:58 PM
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Originally Posted by dddd
Muriatic acid dissolves aluminum.
-Kurt
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03-24-23, 08:17 PM
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Originally Posted by cudak888
It also eats thin steel. I had a steerer tube lose all of its threads and the steerer gain pits in the surface with that stuff.
-Kurt
-Kurt
But you bring up a good point, since it might take a while to burn through a seatpost, and the operator might not know how long was long enough.
So I will have update my earlier comment to add that I recommend only mechanical removal, no chemicals (since they don't seem to be needed).
The caustic chemicals have bodily hazards as well, fumes, spatter, blindness and no doubt possibly death if used haphazardly.
At least they're not flammable!
