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-   -   Thickest, stuckest seat post (https://www.bikeforums.net/classic-vintage/1242255-thickest-stuckest-seat-post.html)

justcynn 11-14-21 04:34 PM

Thickest, stuckest seat post
 
so, the find of the day turns out to have the thickest and very stuck seat post I have encountered. To make matters worse, is about 6-7 inches into the seat tube. This Reynolds 531 frame may not make it...

First I started with Drano, no luck. Then I cut it off and had planned to cut it out and discovered just how thick the side walls are...

I have read the lye ideas, prob not something I would want to try. Mostly interested in cutting it out, but I don't think my sawzall blade will fit. Maybe bore it out with a drill first? other ideas?

https://cimg1.ibsrv.net/gimg/bikefor...32ccdc0c4.jpeg
https://cimg3.ibsrv.net/gimg/bikefor...8d99a8e04.jpeg

seedsbelize2 11-14-21 04:41 PM

Wow.
Awaiting constructive replies.

Bianchigirll 11-14-21 04:51 PM

If you have big bits I’d try and drill it out.

gaucho777 11-14-21 04:54 PM

Wowza, that is a thick post. I’m not an experienced stuck post remover, just throwing out my 2 cents. That said, I would think about using that thickness to my advantage. Perhaps drill through the side of the post and insert a steel rod through the post to gain some leverage. Trying to cut out that thick post seems like a nightmare. Good luck!

noobinsf 11-14-21 04:56 PM

Folks are always suggesting extreme heat, then letting it cool to break the bond. Maybe a blowtorch down the middle of the post? I have ZERO experience with this, so grain of salt, at your own risk, and all that.

clubman 11-14-21 05:10 PM

I just went through this with a Rocky Mountain Fusion. Long post slammed down solid. It took 6 days with multiple applications of strong lye solutions thru the BB to win the war and melt the post. The paint suffered terribly although mild caustic soda won't usually damage quality paint. It's nasty and I won't do it again unless it's a truly special frame. That sounds odd but I would refine the process to not damage frame.

I used hardware lye crystals in 1 litre Mason jars, about 6 tablespoons per jar. Wear protection!

edit. Gotta say, there's an idiot on Youtube who has to be the poster boy for how not to try this. Shorts, T-shirt, shaking a pepsi bottle full of caustic soda. 'Only burns a little' he said, dodging the boiling magma. Unreal.

iab 11-14-21 05:15 PM


Originally Posted by clubman (Post 22307309)
Wear protection!

That's what she said.

machinist42 11-14-21 05:16 PM


Originally Posted by justcynn (Post 22307259)
so, the find of the day turns out to have the thickest and very stuck seat post I have encountered. To make matters worse, is about 6-7 inches into the seat tube. This Reynolds 531 frame may not make it...

First I started with Drano, no luck. Then I cut it off and had planned to cut it out and discovered just how thick the side walls are...

I have read the lye ideas, prob not something I would want to try. ...

"Drano" is Lye, sodium hydroxide.

As you have already started down that path,
And destroyed the seat post,
Give the seat tube a thorough bath.

Lye will wash your troubles away, given time.

Chuck M 11-14-21 05:26 PM

I'd assume the previous owner was a clydesdale. As thick as that is, I would drill and tap it to accept a slide hammer fashioned from all-thread and a hefty piece of metal. But I have access to large taps and drills and I understand someone may not want to make that investment. If it is mushroomed up enough you aren't worried it will fall down inside the seat tube, I'd try to break the bond with a good rap from a hammer.

justcynn 11-14-21 05:37 PM

thanks all for the replies. I have a 3/4 wood spade bit, it does drill into the Aluminum but it wont make the 7 " trip. I also have a couple hack saw blades and while it will be a long job, they appear to have potential to do the job by hand...

also ordered a 3/4" boring bit some skinnier saws all blades with hopes of fitting in there to cut it out, if that doesnt work - lye it is. but this project may get pushed to the back of the stash if it comes to that...

clubman 11-14-21 05:53 PM

I get it but I think it's easier to destroy a frame with a cutting tool than lye. Not that it's the best 'solution'. nyuk.

Bianchigirll 11-14-21 06:07 PM


Originally Posted by justcynn (Post 22307335)
thanks all for the replies. I have a 3/4 wood spade bit, it does drill into the Aluminum but it wont make the 7 " trip. I also have a couple hack saw blades and while it will be a long job, they appear to have potential to do the job by hand...

also ordered a 3/4" boring bit some skinnier saws all blades with hopes of fitting in there to cut it out, if that doesnt work - lye it is. but this project may get pushed to the back of the stash if it comes to that...


Can you tell if the post walls get thinner?

machinist42 11-14-21 06:13 PM

The Things I Tell You Will Not Be Wrong, Whup Whup Whup...
 

Originally Posted by clubman (Post 22307354)
I get it but I think it's easier to destroy a frame with a cutting tool than lye. Not that it's the best 'solution'. nyuk.

No Lie!

(nyuk, nyuk)

justcynn 11-14-21 06:20 PM


Originally Posted by Bianchigirll (Post 22307376)
Can you tell if the post walls get thinner?

oh for sure. its thinner about an inch in, but I dont think I can drill all they way down with what I have. I have my eye on this close quarter hack saw hand tool too. One way or another, that sucker is coming out!

I do plan to blast/powder so not that concerned about the paint - so Lye will be the next try

https://cimg9.ibsrv.net/gimg/bikefor...c81854ac93.jpg

Reynolds 11-14-21 06:30 PM

I'd be careful with such a thick seatpost - too much twisting force could ruin the frame.

Mr. 66 11-14-21 06:40 PM

For where you are in the process I would use some PB Blaster and longer sawzall blades and go cut down the center on opposite sides. I would use the power tool, I would have your frame secured on a table or bikestand so that you can easily see your angle of cut. I also have fashioned a slide hammer out of threaded rod a couple of nuts with washer various sockets, to help tap out.

I've done a few, I did buzz a hole in my first attempt, all since have been extracted with no damages.

Mr. 66 11-14-21 06:56 PM

Here the postless Ron Cooper
https://cimg8.ibsrv.net/gimg/bikefor...93c8420148.jpg
https://cimg9.ibsrv.net/gimg/bikefor...8e010dc8ad.jpg
Here's the Club Fuji that had a stuck post cut flush with the seatlug.
https://cimg0.ibsrv.net/gimg/bikefor...fd0ede23ff.jpg
https://cimg1.ibsrv.net/gimg/bikefor...df372a385f.jpg

justcynn 11-14-21 07:11 PM


Originally Posted by Mr. 66 (Post 22307430)
Here the postless Ron Cooper


Here's the Club Fuji that had a stuck post cut flush with the seatlug.

looks like one of those was fairly thick as well, couple of questions. Did you cut it off flush, what kind of saw blade/saw did you use to get inside the seat post, at present - my blade won't fit? I assume the cuts were towards the top of the seat post and then how did you get it moving? thanks!

nevermind, I see your saws all and blades - thanks for sharing!

Duke7777 11-14-21 07:40 PM

I recently drilled out a thick frozen stem using a hand drill, step bit and extension. This required the stem to be cut off fairly close to the top of the steerer tube. It worked very well, although it's slow and requires cutting oil to resist galling and jamming. Assuming the original hole is centered in the post, the step bit will follow this hole very well and leave you with a thin tube that can be be collapsed by driving a thin screwdriver down the side. The trick might be to come up with a step bit with a suitable maximum size. For the stem, I used a 7/8" bit with the largest step ground off, reducing the maximum size to 13/16 or 20.6mm. For a seat post you would need a 1" step drill, and this size seems to be uncommon.

https://cimg7.ibsrv.net/gimg/bikefor...471ddbdca4.jpg

WaveyGravey 11-14-21 07:41 PM

Any recommendations for avoiding this situation? Perhaps anti seize applied to the seat post? Thanks

FBOATSB 11-14-21 07:57 PM


Originally Posted by WaveyGravey (Post 22307478)
Any recommendations for avoiding this situation? Perhaps anti seize applied to the seat post? Thanks

1) Make sure your seat tube is clean and free of rust/burrs. Also make sure the binder bolt and clamp area is in good condition and lubed
2) Make sure your seat post is the right size (slides in and out without zig zag twisting)
3) Use a light coating of grease or anti seize.
4) And most important of all, take it out once in a while to clean and re grease. This includes quill stems.

justcynn 11-14-21 08:17 PM


Originally Posted by Duke7777 (Post 22307476)
I recently drilled out a thick frozen stem using a hand drill, step bit and extension. This required the stem to be cut off fairly close to the top of the steerer tube. It worked very well, although it's slow and requires cutting oil to resist galling and jamming. Assuming the original hole is centered in the post, the step bit will follow this hole very well and leave you with a thin tube that can be be collapsed by driving a thin screwdriver down the side. The trick might be to come up with a step bit with a suitable maximum size. For the stem, I used a 7/8" bit with the largest step ground off, reducing the maximum size to 13/16 or 20.6mm. For a seat post you would need a 1" step drill, and this size seems to be uncommon.

https://cimg7.ibsrv.net/gimg/bikefor...471ddbdca4.jpg

thanks for the suggestion, my ace hardware has one that goes to 1", but its around $60 including Tax. If all else fails, I will try it though.

bwilli88 11-15-21 05:24 AM

I had to do this with my Zunow.
Found a 22mm drill bit at a local shop.
https://cimg6.ibsrv.net/gimg/bikefor...f55c321a9f.jpg
https://cimg5.ibsrv.net/gimg/bikefor...ed102b7ff0.jpg
https://cimg3.ibsrv.net/gimg/bikefor...0cb48fde19.jpg

Trakhak 11-15-21 06:37 AM

For future reference for others who might encounter stuck seatposts:

When we used to run into that problem at the bike shop where I worked, we'd take the bike to the auto repair shop next door, where a mechanic would use a pneumatic hammer on the underside of the seat clamp. The seatpost would pop out in a few seconds with no damage to the frame.

Odd that I've never seen this suggestion in any of the stuck seatpost threads I've come across here.

fishboat 11-15-21 06:58 AM


Originally Posted by justcynn (Post 22307526)
thanks for the suggestion, my ace hardware has one that goes to 1", but its around $60 including Tax. If all else fails, I will try it though.

While I'm a good customer of my local Ace..for the last 30 years...you can buy step bits on amazon for $15-$25. Some are low quality(though some good brands are there too)..you're drilling out soft aluminum, slightly more challenging for a bit than a good hardwood. Actually a cheap bit might be a plus as you'd like it to stop cutting when it hits steel.

Seems like a good method as long as the starter hole is centered. I had a bike shop remove a stuck post years ago. While they got it out and only charged me $100(3+ hours they futzed with it), someone used a sawzall at some point and sliced a small (3/8ths inch) slit-hole in the seat tube. Small, but definitely there once the paint chipped off enough to see it. No idea if they knew they did it. It wasn't visible initially as it didn't come through the paint. Ended up giving the bike(a very nice bike..) to the son of a good friend. An added "decal" electrical tape pinstripe around the seat tube and good to go. He's 26 and starting an adult cycling habit. He loves the bike..so did I.. :)

justcynn 11-15-21 07:34 AM


Originally Posted by fishboat (Post 22307830)
While I'm a good customer of my local Ace..for the last 30 years...you can buy step bits on amazon for $15-$25. Some are low quality(though some good brands are there too)..you're drilling out soft aluminum, slightly more challenging for a bit than a good hardwood. Actually a cheap bit might be a plus as you'd like it to stop cutting when it hits steel.

Seems like a good method as long as the starter hole is centered. I had a bike shop remove a stuck post years ago. While they got it out and only charged me $100(3+ hours they futzed with it), someone used a sawzall at some point and sliced a small (3/8ths inch) slit-hole in the seat tube. Small, but definitely there once the paint chipped off enough to see it. No idea if they knew they did it. It wasn't visible initially as it didn't come through the paint. Ended up giving the bike(a very nice bike..) to the son of a good friend. An added "decal" electrical tape pinstripe around the seat tube and good to go. He's 26 and starting an adult cycling habit. He loves the bike..so did I.. :)


agreed, he had suggested going to a 1" max step bit which I only could find at Ace, I think that would be cutting it pretty close 25.4MM in a 27.2MM seat tube. I ordered the one he pictured with a max of 7/8 for $10 from Amazon. That should be 22MM which is the same as another person posted using a 22MM bit. I hope to avoid the saws all, but if I do need it, I have to bore the hole quite a bit bigger to fit it in there anyway. I could also use a hand hacksaw to finish it off if need be

thanks for the input, this sucker is coming out!

SJX426 11-15-21 07:46 AM

I have one experience with a stuck post.
Treated it for months with Kroil. At the time it belonged to a person who used the same storage room at work. The saddle clamp was a separate part and had broken free enough to just rotate.
First step was to drill a hole through it to use it as a leaver for twisting. No go.
The bike was partially stripped during a weekend (Wash DC) and he replaced the bike. I offered to purchase and he sold for $50 sans wheels, stem, handlebar and brake levers.
All my attempts of a mechanical removal failed to extract it but mangled the remains of the post.
https://live.staticflickr.com/5643/2...f7ee5b1e_b.jpgP1030267 on Flickr
Even tried to saw it out but it was too far in, maybe 12". Note the bolt configuration to spread the saddle lug clamp.
https://live.staticflickr.com/5773/2...b68f0b81_b.jpgP1030271 on Flickr

Gave up and attacked with Lye.
Did this outside because the chemical reaction is H2 and it gets hot. Tried to plug the clamp area and inverted the frame.
https://live.staticflickr.com/5633/2...d9a61658_b.jpgP1030273 on Flickr

Tried the Drano approach but it was not aggressive enough. Went directly to lye crystals. Pored it into the BB and got a quick reaction with lots of vapors and foam.
https://live.staticflickr.com/730/22...baa77845_b.jpgP1030283 on Flickr

Not enough heat to damage the paint but you can't touch the frame. Located the clamp as far from the saddle lug as possible, only 100cc of lye solution at a time.
I think I did 4 treatments. Some paint damage from the leaks.
There was progress.
https://live.staticflickr.com/5662/2...a74c6b4d_b.jpgP1030290 on Flickr

I finally got it out
https://live.staticflickr.com/1660/2...d061ae81_b.jpgWP_20160107_001 on Flickr

Paint damage is what it was. Better than trashing the frame.
https://live.staticflickr.com/5758/2...b7e78b52_b.jpgLangster Seat Cluster by Patrick Boulden, on Flickr

The wheels were purchased off craigs list and the rest was in the stash except the BB needed replacement and the 42 tooth ring was replaced with 46. Rear 16t sprocket purchased as well along with a chain.
https://live.staticflickr.com/5641/2...765db483_b.jpg2010 Langster Steel 61cm on Flickr

viperocco 11-15-21 08:05 AM

That has got to be the craziest seat post I have ever seen. I would go with drill it out till it is thin enough to peel away from seat tube?
I too would like to take a stab at a stuck seatpost bike just for ***** and giggles. Good luck!

ZudeJammer 11-15-21 10:23 AM

damn thats a thicky. the large drill bit method looks easiest method. I dont recommend using bismuth to embrittle the post cause you will still need to grind it out and its messy

jdawginsc 11-15-21 05:13 PM


Originally Posted by justcynn (Post 22307259)
so, the find of the day turns out to have the thickest and very stuck seat post I have encountered. To make matters worse, is about 6-7 inches into the seat tube. This Reynolds 531 frame may not make it...

First I started with Drano, no luck. Then I cut it off and had planned to cut it out and discovered just how thick the side walls are...

I have read the lye ideas, prob not something I would want to try. Mostly interested in cutting it out, but I don't think my sawzall blade will fit. Maybe bore it out with a drill first? other ideas?

https://cimg1.ibsrv.net/gimg/bikefor...32ccdc0c4.jpeg


First of all, what the %$#^%@&#$ seatpost is that thick?

Secondly, that photo is cool...it almost looks like an acrylic painting.


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