Why is it that my conversion gets 3x dirtier than my road bike? While I ride my conversion everyday (commuting) I usually ride my nice bike the same distance on the weekends, so I don't think it is a usage thing.
I would think that with less stuff to spread grease and grime and whatnot, my fixed would be cleaner, but the chain and rear wheel get disgustingly filthy in a rather short period of time.
It's only the rear wheel, though. The front wheel (even with a brake) stays nice and shiny.