Originally Posted by
Esos1
So could one just leave a steel frame with a stuck
aluminum post out in sub freezing temps and add pb blaster everyday? Would that be worth trying?
Doubtful, but try if you've never done anything like this before.
Problem being: "cold-soaking" the frame w/ post has the two metals contracting from temp change. PB Blaster, administered before you leave frame & post to 'chill out' also grows less able to penetrate where it needs to be to do what you desire.
Using something cold enough on the insides of the seat post ought to cause the post to shrink more in a short interval than if left in a colder temp environment over time. It's the sudden 'shock' value of the chillin' that's important. Cold and fast, and only on the aluminum. The PB (or similar) is simply to aid in making the interstices between the two metals more likely to move when sufficient force is applied to separate the two.
Likely as not it will still be a tuffy to separate the two, but ought to be easier than trying to do it with everything at room temps and dry as a bone.
Originally Posted by
Steve B.
If the post is finished, stick an old saddle in it, put the bike upside down and stand on the saddle, wiggle the bike to try to loosen the post.
That's how I'd approach this: one is able to apply 'maximal' force once the PB has been allowed to work in between the stuck bits. Chillin' the seat tube gives the PB more room to work its magic.
Adding vibes may or may not help... I'd be inclined to try using a multi-tool w/o cutter installed to add a bit of vibration during the twisting of frame if twisting proves insufficient alone. Hold the head end of the multi-tool (NOT the cutter attach mech!) against seat tube's exterior while another pair of hands twists the frame w/ their feets standing on saddle.