Seized seatpost...VICTORY!

[brucers]

Tried wd40, tapped with hammer, upside down in vice. Seems all that is left is to cut off and file away till next Xmas! 2 things....is there anything else I can do before last resort of file. 2nd, any tips n hints on file process.....how low should I cut off post. Steel frame, probably steel(?) post, late80's, early 90's Sparta.

Ding dong merrily on high and all that to you all.

 

[PHL67]

I usually heat them up and put post end into vice tighten up severely then start to twist the frame. I usually use GT85 first, leave for the day the go with the heat.

Not failed me yet.

Some people I know use full sugar Coca Cola as that eats anything, especially corrosion.

Hope this helps.

 

[simongt]

A method I read of once is to invert the bike, drill a suitable sized hole through the seat pin - inverted, you won't get drill swarf in the bottom bracket. Bike back upright, apply suitable lube and leave to work in. THEN, get a tommy bar, put it thru the hole you've drilled and gently twist each way. Works apparently. All you'll need then is a replacement seat pin.

 

[brucers]

Ahhh the coca cola option.....forgot about that...yes it helps....how much will depend! Thanks.

Found Sheldon advice about cutting the length of the tube inside then rolling it in on itself....not sure how I'd get enough grip to actually rolling it especially given my vice could not hold against me twisting the whole bike against it!

 

[brucers]

A method I read of once is to invert the bike, drill a suitable hole in the seat pin - inverted, you won't get drill swarf in the bottom bracket. Bike back upright, apply suitable lube and leave to work in. THEN, get a tommy bar, put it thru the hole you've drilled and gently twist each way. Works apparently. All you'll need then is a replacement seat pin.

Pondered that but not sure my drill is up to it (yes it's crap) and that I have a bar tough enough!

 

[brucers]

Definitely steel and steel?

Frame def yes.....seatpost is one of those standard types of that era.

 

[Cycleops]

If you can get hold of a slide hammer:

View: https://youtu.be/S3ek2GeZzE0


The coca cola method;

View: https://youtu.be/tiePnfdpIQA

 

[brucers]

My shed has all sorts of rubbish....but a slide hammer no!!

 

[rrarider]

The best penetrating fluid used to be called Plus Gas. I believethat it is still available. WD40 and GT85 are just lubricants.

 

[Randomnerd]

PlusGas is good.

 

[Drago]

50/50 mix of ATF and white spirit.

 

[brucers]

50/50 mix of ATF and white spirit.

Whats ATF?

 

[alicat]

Automatic transmission fluid according to Google.

 

[ColinJ]

It is interesting reading these suggestions because I discovered that I have managed to get my titanium seatpost stuck in my aluminium Cannondale. I was aware of the risk but forgot to take precautions ...!

It is not imperative that I loosen it because the saddle height is pretty good but I did fancy moving it up by about 5 mm to see how that felt. I don't want to damage the frame or the post so I won't try anything too drastic, but if any of the non-destructive methods are likely to work then I will give THEM a go.

I think that Al expands much more with heat than Ti does so I thought about aiming a fan heater at the point where the post goes into the seat tube and seeing whether thermal expansion would break the bond between post and tube.

 

[User32269]

I've always found squeezing a can of spinach until it bursts, then swallowing the contents as they drop, helps me loosen any stuck metal?