Originally Posted by ibafran
It is my experience that WD-40 is a terrible chain lube. I get 25k miles using real lube and/or 120wt gear oil from an oiler.
I lost a perfectly good chain in 12k miles. No ammount of WD-40 was helpful. The chain dried rapidly and a red oxide/dust appeared rapidly. O-rings got hard and cracked off.
WD40 alone should never be used as a lubricant. It dries and evaporates fairly rapidly, that it will not provide much lubrication after only a few hours. It is, however, GREAT for cleaning a chain, and removing gunked on grease.
I use WD40 for cleaning the chain off, getting any dried lube and gunk off, then apply DuPont multiuse Teflon lubricant (for bikes) on there. So far, so good: 23,000km and the chain is like new.