coker seat post stuck in frame

The aluminum seat post on my new Coker Big One is STUCK in the frame tube.

When I was adjusting the height of the seat, I bottomed out the seat tube on the metal pin that keeps the seat tube from hitting the tire. I believe that the bottom of the aluminum seat tube is now flared out enough to wedge it in the frame.

If I had gotten the CroMo seat post, I’m guessing that it would not have bent like the aluminum.

Any suggestions for getting it unstuck? Since it is almost all the way into the frame tube, perhaps the safety pin should be removed and the the seat post pushed through. Then the end could be smoothed down so that it could be extracted.

I’m about to take it to the REI bike shop shortly to see what they can do.


Not sure what the best method is for un-sticking aluminum from aluminum, but you can probably find info about it online (bike forums, etc.). If you do take the “safety” pin out, please let us know how you did it. I tried drilling out the one on my V2 (maybe with a dull drill), and gave up after not making a dent…

I don’t know if this will help

It sounds like you think the end is flared. In that case, you can easily twist the post, just not take it out. In that case, I suggest brute force. Perhaps fasten the frame to something solid, and pull the post out with a cable come along. These are handy tools, and quite cheap. The flare on the end is alum, so it will deform back.

If the post doesn’t twist, there is the temp-size difference idea. Heat the frame post with a propane torch, then stuff a sock stuffed with chipped ice down the seat tube, though you have to saw the 4 bolt part off to try that.


Twist and pull by whatever means possible. I’ve had a pair of scissor jacks between the frame crowns and seatpost flange in the past :-). Sometimes clamping the post securely in a vice will allow you enough leverage to twist and pull the uni frame off it.

If you decide you need to do it destructively, saw the post off about 2
inches above the frame. Then take a hacksaw blade and reaching in the
seatpost from the top, cut a slot in it from the inside-outward being careful not to cut into the frame. Usually one slot is enough to relieve the binding and allow you to pull it out. If not, cut a second slot on the other side. Then twist and pull. If you think the problem is only the flair at the bottom, and you can get to the seatpost bottom through the bottom of the fork crown, you might try cutting a slot only in the bottom of the post and see if that relieves things. You’ll be less likely to damage the frame from cutting too far, and, depending on your height, might even be able to reuse the seatpost.

I’d recommend carefully inspecting the inside of the frame for any burs that might be cause of the problem, and either dressing them with a small, round, file, or using an adjustable ream to clean it up (your LBS should have one).

Just pull like crazy untill you get a hernia. If that doesn’t work keep pulling you’ll get it out:) Just don’t do anything rash. You don’t want to destroy your nice coker frame.

happy ending

Alas, my tale of woe had a happy ending. I removed the wheel and took the setapost/frame assembly to the nearby REI store and the helpful bike repair person helped me get it apart.

We ended up wrapping the seatpost in a rag, clamping it in a vise and worked it off. After deburring the frame tube and applying some grease, it all went back together fine.

Thanks for the replies…tom

removing safety pin

The pin on The Big One looked like it was made of spring steel and could be tapped out with a punch. Your Mileage May Vary…tom