Seat post stuck!

[northwest monkey]

Could do with a bit of help to be honest! I was at an auction a couple of weeks ago & a bike popped up. Nobody seemed interested, so I figured I'd have a pop & for not a lot of cash (under £20!) I became the proud owner of a Specialised Rockhopper. By any stretch of the imagination, it isn't in perfect nick (seems to be about 4 years old), but everything seemed present & correct.

Only problem is (apart from me being a lot less fit than I was 25 years ago), is the seat is too high and I can't lower it! I've tried plus gas & also widening the clasp at the back of the post tube, but still no joy. I'm planning on stripping the bike down at some point, so would heating the tube up (blowtorch or hairdryer?) be of any use?

[Some Gump]

Seat post in vice, then yank / twist the frame. Might kill the seat post, but if it does get a cheap one from eBay for under 10 quid.

[47p2]

Has to be careful with the seatpost on the vice as twisting the frame can sometimes damage it beyond repair. Turn the frame upside down and remove the bottom bracket and fill the seat tube for a few days with either of the following
Coca-cola
Plus Gas
50/50 mix diesel and ATF

[TwistingMyMelon]

Or you can hacksaw it off and then hacksaw the post out using just the blade

Painfully slow but will get there

[northwest monkey]

Cheers chaps - some good ideas

[Kell]

http://www.theseatpostman.com/

[Watchman]

Kell said:

http://www.theseatpostman.com/

How does he do it? I was wondering whether some sharp vibration might work. Any idea?

Personally, never had a problem that couldn't be solved with plus gas or similar.

[Barchettaman]

No-one really knows, he's made the tooling himself and is (unsurprisingly) pretty secretive about how he does it.

The last really stubborn one I had came out after being put in a heavy-duty bench vice and turning the frame.

• IMPORTANT* : I put an old rear hub in the dropouts to reinforce the rear triangle.

Looking at some of the links on Retrobike it seems a slide hammer is the way to go, if possible with the frame mounted upside down from roof rafters or similar.

[Steve vRS]

Yup. Removed a carbon post from an aluminium frame with brute force and a vice. The heat generated as the corrosion. One was broken was incredible!

I swore I would always remember to grease the shaft regularly but soon got out of the habit. Fnarrr fnarrr.

[dogbucket]

Watchman said:

How does he do it? I was wondering whether some sharp vibration might work. Any idea?

He says it is straight withdrawal. So my best guess would be a framework which holds the frame down by the bottom bracket and some sort of reverse bearing press attached to the seatpost to pull it out.

[Kell]

Watchman said:

How does he do it? I was wondering whether some sharp vibration might work. Any idea?

Personally, never had a problem that couldn't be solved with plus gas or similar.

I've never used him, but remember seeing the link a few years ago.

[hast2]

TwistingMyMelon said:

Or you can hacksaw it off and then hacksaw the post out using just the blade

Painfully slow but will get there

I've done it this way in the past, but don't cut it flush, leave an inch or 2 so that you can either get a pipe wrench on it to twist it, or you can try knocking it down the way, after you have run a blade down it, then pull it back up once you have got it moving/freed off.

Also you can buy handles for holding hacksaw blades for using in this way, or just wrap a bit of gaffer tape round one end to use as a handle.

http://www.screwfix.com/p/forge-steel-mini-hacksaw-10/2514c