I have a Jamis Beatnik (love) and ride on the single-speed side of my hub. I'm wondering - derailleurs seem to me like they might 'stress' the chain (even if only slightly) more than single-speed in the process of changing gears. Are geared bikes' chains harder to maintain / shorter lived than single-speeds'?
(Background: I noticed I hardly have to clean my chain on my single speed, and it always looks great and feels tight.)