Hi there,

I’m helping a friend to get his bike back into shape. We’ve already done quite a bit on it, but my main problem is, that he’s not moved his seat post in like 5 years (I’ve no idea how thats possible because the saddle is too high up for him making it really hard to ride properly). So now its completely stuck.

I’ve tried to move it with grease or soap but so far nothing worked. The other thing is that he has a carbon fibre frame, so don’t really want to force it too much.

He said he asked in a bike shop but they said that they didn’t know what to do either.

Any ideas what I could try?

Ta, Henni

Is the post carbon as well. I presume it is?

No the seatpost is aluminum.

Ali can powder up when bare metal against another material. Tbh not sure how carbon reacts to normal lubs and sprays. You could try heating and cooling the post gently too try and get some movement. Do this a few times to see if anything will free.

Whats a good way to heat it up?

Have a look here

Get some proper penetrating oil from somewhere (halfords sell it) and spray this on the area several times a day for a few days. Hopefully this will work it’s way in and loosen things. After that try and shift it, if it still fails then take the saddle off and get the head of the seatpost in a vice and use the frame as a lever. Not too gentle but probably as gentle as it gets!

Check the bottle mounts have not clamped it into place.

Remove BB, turn bike over and soak with plus gas from BB shell.

Take saddle off and smack the post down with a block of wood + hammer. As soon as its gone down a bit, put saddle back on and use it to twist the post out.

I would be wary of heating the carbon fibre, it tends to do the opposite of metal and shrink when heated.
So by heating it up you are shrinking the carbon and expanding the metal, therefore may end up tighter.
With it being freezing outside I would see if you can leave the bike outside for a few hours, that may make the metal contract a little.

Depends how valuable the frame is, before deciding if I’d take a hammer or a blow torch to it but I’d say lbs. And if the lbs has no idea, find a decent one that does.

Yeah don’t hear the carbon! Just the post at the top. But I would use a lube spray first as this is last resort sort of thing. Or as mention above cool the bike. The Ali should move slightly more than the carbon.

I was under the impression that carbon does not react well to grease/oil and can swell.

The definitive list from Sheldon Brown here.