We get some bikes in from time to time with pretty nasty corrosion.
Generally it's from people living in Montare on the coast (do they have
more-corrosive fog than other areas along the coast? Sure seems like it!)
but there are also many that come in that live their lives far from the
coast. When asked where they store their bikes,it's inevitably the garage,
and we've thought the culprit to have something to do with water heaters,
furnaces, that sort of thing. Maybe water softeners, except that few in this
area would use a water softener. Then I started noticing a pattern... lots
of these bikes were coming from "nice" areas. Atherton (a very well-off
community) stands out. I called my inside tech guy at Trek (who's nothing
short of amazing; he's been there for over 25 years and is one of the
reasons I enjoy selling Trek because he can figure things out that I can't)
and he knew exactly what is going on.

Swimming pools. The chlorine and other chemicals used for swimming pools are
incredibly corrosive. Just after learning this, a good customer of ours
comes in for something minor to check out on his bike, and I mention
coversationally what I'd just learned. The first words out of his mouth were
"How far away from the equipment does it need to be?"

So if you've got a swimming pool, keep your bike a good distance away from
it and any pool equipment. Don't store it in a shed with pool chemicals,
don't store it in a garage near pool equipment. Chances are, this is obvious
to many, but it hadn't come to my mind before this.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA