rusty deraileur springs- should I care?
 

my 2008 C'Dale bad boy disc (sunday bike), and especially my 2005 C'dale bad boy (beater bike), have rusty derailleur springs. They work fine, of course. Keep both bikes in clean, dry condition- in garage when not ridin. SW Ohio, USA. They're both seen rain, specially the beater, but I dry/clean right after a wet ride, and it doesn't happen often. Is this common?

If everything works fine, then it's probably not a problem. You might as well oil those springs whenever you oil your chain.

slight cosmetic rust isn't a problem, but if you allow it to get deep into the spring it will be. It doesn't take much rust to make a spring get brittle, fatigue and crack.

Since you can't replace them anyway, you might as well live with it, but keep an oil film on them to keep it managed.

Spray can of Boeshield T9 works great for something like this.

Maybe a couple drops of WD40 on the spring?