Holdsworth Special - Frame Rescue

[dwscrimshaw]

Yes, I've seen several methods, one pushes against the BB. Know how tight this was I tied to find a way that did't stress the frame too much. I had to cut it to allow it to collapse when being pulled out. It was quite long so cutting it at the bottom was difficult, took several sessions to complete. Not sure why the original owner thought it was a good idea to cut the top of the post off!

Still starting to build it up now

 

[CBguy]

I would be interested to know how that (caustic soda) works, there was evidence of the penetrating oil up between stem and tube, but still wouldn't come out.

Caustic soda (NaOH) basically dissolves aluminum without reacting with steel. (Doesn't necessarily need to penetrate between seat post and tube.)

I'm no chemist but found this on Wikipedia:
Sodium aluminate is formed by the action of sodium hydroxide on elemental aluminium which is an amphoteric metal. The reaction is highly exothermic once established and is accompanied by the rapid evolution of hydrogen gas. Sometimes written as:
2 Al + 2 NaOH + 2 H2O → 2 NaAlO2 + 3 H2

Description:
http://www.classiclightweights.co.uk/seatpin-rest.html

 

[dwscrimshaw]

I must admit that example from CL is impressive, I used penetrating oil for longer than that with no effect. I guess with with my back ground I gravitate to mechanical methods and have been skeptical over such methods as 'dissolving'.

Equally the science is clear and the evidence looks good, I'll certainly give it a go in future if in the same situation.

 

[dwscrimshaw]

Nearly there, just need to set up the gears properly and take it for a spin.

 

[Midlife]

That's a lot of stem showing, is it an extra long one like a Nitto Technomatic?

Contrasting blue looks nice

 

[dwscrimshaw]

That's a lot of stem showing, is it an extra long one like a Nitto Technomatic?

Contrasting blue looks nice

Yes, I think its a MTB stem, but does the job as the frame is bit small for me really. I have a seat pin push down inside too due to the damage caused by getting remains of old stem out. This one sits over the reduced OD of the pin to make it more secure.

 

[dwscrimshaw]

Finished. Took out for 5 mile spin, goes ok, couple of adjustments made when back. weighs in at 11.1kg, which seems a bit heavy, but lighter than with the MBK frame. Not sure i'll see much of a gain tough. Anyway rather ride this than what I had before.