TOC seat post removal help wanted

[JO BO]

Okay what is the method to extract this seat post? I have never had one like this before, I loosened nut a little but cup started turning so held and turned some but could only pull up post little not sure what to turn or direction etc. don’t want to force and break something
Turning the nut doesn’t seem to make it rise from the cup.

 

[JO BO]

Finally got nut from cup but not sure of next step. I can move the treaded part a bit through the cup but I wonder if the threaded part should be on post stem or fixed within the cup. When the nut was in the cup I could push the post down and it was very loose in Down tube

 

[Andrew Gorman]

On one year of Columbias (1902?) with a nut at the top of the seatpost there is a loose wedge that expands the seatpost. Try knocking and turning the post- it it's there it might fall out and free the post.

 

[JO BO]

Thanks I will give that a try. I wonder if I tightened the post into that threaded piece as I was able to pull the post up a couple of inches at the start when I didn’t have the nut loose from the cup yet. Was trying to figure it out

 

[redline1968]

Spray the area with oil take a rubber mallet and tap it side to side for a while until the oil leaches into the collet and then eventually it should loosen up if it's too tight ..if you can get it to one side and then tap the underneath the seat post to force push the post up that might work too..

 

[Rusty McNickel]

Not knowing if you are still in this bind, but.....

If you know it, it may be helpful to post the manufacturer of this bicycle. There are a few different mechanism in binding the seat post using this type of cinching nut. Knowing the manufacturer, a CABER may be able to provide details of the inner workings giving you better insight as to how to approach it.

I have two examples I can provide but from appearances may not be exact to yours. But still they may provide some food for thought on ways to proceed.

The first is a Columbia 1899.

The other is Victor 1899

I wish I could provide better details on the Victor but it is captive in the frame and I have no need to remove it otherwise. I can say the there are two internal split tapered sleeves that wedge against each other as the nut is tightened. The catalog view is not that great but the only way I could figure how to post it here.

Hope this may help somehow. Good luck.

 

[Rusty McNickel]

It seems in any configuration, force needs to be applied to a partially engaged nut to reverse the tightening process and break the wedge. Whether that be upward or downward depends on the design I assume. That's where it would be helpful to identify what the make is to have a better view the internals. At the very least, use plenty of penetrant.

 

[Jollyride]

Kroil.

 

[Archie Sturmer]

For mechanical devices such as those, it might be a good idea to figure out what the two sets of threads do; (generally some kind of pushing, pulling or clamping force).

Not sure about the larger diameter threads, but thinking that the smaller threads will raise and tighten a collet onto the seat post?

So perhaps reattaching the nut, and backing off the threads just a bit, and and tapping the nut down might lower and loosen the collet?

Not sure what the outer piece with the larger diameter female threads might be attached to underneath?

 

[WetDogGraphix]

I know on my 35 Hawthorne with the collat seat post, I fought it for a while... I finally did what's posted above. Both of the above seem to work the same way...
I finally put the nut back on so as not to damage the threads, then got a closed end wrench that sat on the nut, and hit it lightly with a small ball peen hammer. I got the nut down, but needed to unthread it a tiny bit more, hit it, and the post came loose.
Both of the shown pieces seem to work the same way...

Good luck... Once you get it out, I'd love to see how it works...