stuck seatpost

Collumbo

So here's the deal... it's stuck. Won't budge. The bike has been sitting idle for about 6 months. It is a scandium frame. The seatpost is carbon lacquered alloy (it definitely ain't a carbon-only one). The last time the seat post was removed was probably this time last year. It was lightly greased when I last inserted it 12 months ago. I am guessing that a max of maybe 10cm of seatpost is in the seat tube, maybe even just 8cm.

I have tried a silicone spray, a spray for seized metal objects (it's not wd40 - some other brand of stuff that smells similar, maybe a bit oilier). I've let it sit there overnight. I've tried getting some movement with the bike upside down, down side up, left-right, right-left... The thing just won't budge. It is a serious upper body workout.

So I came across this:
http://forums.roadbikereview.com/showthread.php?p=1458136
specifically... this bit...

Step 1) Pull your cranks and BB
Step 2) Cut the post approx. 15mm from the top of the seat tube. You'll see why in a moment.
Step 3) Take the hacksaw blade out of the hacksaw and wrap one end with a piece of a handtowel and tape it up that way. This is now your handle.
Step 4) Start to cut the seatpost down through the middle (hole). Make your cuts at 12, 3, 6 and 9 o'clock. Once you've made the vertical cuts to a reasonable depth (through the walls of the carbon post), you'll be able the use the 15mm portion at the top as your leverage point.
Step 5) Grab the 15mm top portion with a pair a Channel Lock style pliers and simply crush the remaining seatpost. If it doesn't crush, cut a bit more with your modified hacksaw blade.
Step 6) Once the post has collapsed on itself, with your help (of course), it will pull right out of the seat tube. You may have to (very carefully) push a small screwdriver blade down between the seattube and the now partially collapsed post to break the seal between the two.
Step 7) Clean all of the crap out of your BB shell and re-install your cranks and BB.

Am I mad to try this? It sounds straightforward, just time consuming. My worst scenario is obviously damaging the frame which is nice and expensive. The destroyed seatpost ain't a problem. I can imagine a bike shop charging a nice few quid to do this as it's man-hours that could be spent doing something else.

Opinions? Anyone tried it?

Needless to say I won't make the mistake again...

kona

Seat post in a vice, use the frame as a lever. Grease can break down the lacquer on a carbon fibre part, so your advised not to, it would be mentioned in the box you got the part in. However this is not likely to be a issue here. I hope you get it sorted, scandium is a seriously expensive metal.

Al Wright

Check out Sheldon Brown,
http://www.sheldonbrown.com/stuck-seatposts.html. point 11.

The problem may be that that the fit is tight so that pulling apart increases the grip of the frame on seat post (common on carbon frames/seat posts). The trick is to push the frame off the seat post.

sunshinyday

try using some sachets of vinegar, the ones you get in diners


i typically usethem with carbon parts if they are found to be seized, its always worked well for me.

Collumbo

Hadn't tried the vinegar - will give it a shot. I'm in a rush to fix this. Still curious to know if anyone has tried the cutting out method? I know I can at least get that done tonight. Problem solved. New seatpost... move on.


Regarding sheldonbrowne... I read it. But what on earth does this mean?

From point 11:

The best way to do it is not puling on the outer tubing, but pushing the big tubing off the small tubing, just pressing on the edge of the outer tube while pulling on the end of the inner tube.

I couldn't quite follow the entire paragraph where he has his eureka moment and gets the post out. Two or three pictures would have told me everything. But I get the gist of it - basically he's pushing the frame away from the seatpost. I have a feeling this needs a bit more welly that just that. It's very very stuck.