Originally Posted by
cale
If your chain is wet, why not dry it off with a shop rag? Using a chemical to remove water from a wet chain sounds like EXACTLY the sort of use that the makers of WD 40 would hope you would do. It is like using oil to push water out of a bath tub. It's just not necessary to discharge that many pollutants into the atmosphere. We're supposed to protect the earth, not use it for our own purposes. If you get my meaning, and I mean it in the sincerest non-argumentative way possible.
Because drying the outside of the chain doesn't dry the chain. They invented WD40 for exactly this reason; it is intended to displace the water you can't get to with your rag.
If your chain is well lubed a little rain isn't going to bother it but if your ride for a couple of hours in rain, as I'm forced to do occasionally, the rain will wash away most of the lube and in these conditions WD40 is useful. A can of WD40 lasts me a couple of years. I commute about 12,000km/yr on my bike so I'm comfortable with my impact on the earth.