Originally Posted by
neil0502
Wait.
I know you're an ME (right?), so I value your opinion, but ...
Lemme' re-phrase, and please tell me if I read you right. I hear you saying what I always say: it's a lube, but there are better lubes for nearly any bike-application. It WILL provide reduced wear relative to NOT using any lube, but most basic lubricants (including home brew) will provide BETTER lubrication.
Is that a fair characterization?
WD-40 isn't good enough to resist the extreme pressure at the pin and bushing interface. That's what my test proved. The other lubes that I mentioned are.
WD-40 is fine for light duty lubing like derailleur pivots or even the jockey pulley bushings (not ball bearing types).
I've used a Campy 10 chain (homebrew lubed) for 6,000 miles and measured about 1/3 of the "allowable" .5% elongation, so I know that it works. At that mileage, the chain was still shot, due to roller wear and side wear, but not elongation. Most, perhaps all, other chain brands will elongate to .5% after far fewer miles.