Stuck seatpost? Freeze it out......

[mk one]

Hmmm, wonder if this will work on my Ti frame. Going to be getting a can of freeze next week me thinks

 

[Twisty]

I thought it was quite common to do this, I've been freeing stuff by blasting it with my air compressor

Cooling should work just as well for Aluminium post inside titanium, probably work for carbon fibre too
Other combinations, e.g. carbon or Ti post in Alu frame, might not work quite as well.

Brake bleed nipples
Using 6 point sockets helps greatly.
If it is my own car I like to replace with these http://www.speedbleeder.com/

 

[mk one]

I thought it was quite common to do this, I've been freeing stuff by blasting it with my air compressor

Cooling should work just as well for Aluminium post inside titanium, probably work for carbon fibre too

Thanks for that not going to claim to understand the chart but will give it a go

Cheers

Mark

 

[Twisty]

not going to claim to understand the chart but will give it a go

Haha. Sorry, sometimes I forget I am a man of science.
Basically a larger number means that the material changes size more with temperature.

So for cooling to work the captive part needs to have a larger number than the part surrounding it, for heating to work the captive part needs to have a smaller number than the part surrounding it.

E.g.
Aluminium seatpost inside Steel 22.2 - 12 = 10.2 so for every degree celcius/Kelvin that you decrease the temperature the aluminium contracts 0.0102mm more than the steel which helps to free it.

Ti seatpost inside an aluminium frame 8.6 - 22.2 = -13.6 so for every degree celcius/Kelvin that you decrease the temperature the titanium contracts 0.0136mm less than the aluminium so just wedging it firmer in place, heating on the other hand, the titanium will expand less than the aluminium which will help to free it.