I just rebuilt/repainted my singlespeed (new crank, hub, rims, tires). It rides like a dream. Just today i did about a 20mile ride. Anyways, the hub I have is a Wite Industries Eccentric Eno, which I believe is supposed to be used with the middle chainring on the crank. Well, when I built it, I wanted the bigger ring, so now it is set up on the outside ring of the crank. This of course makes my chainline a bit off. Is this really a big deal, like is it going to damage anything? Would having a perfect chainline benefit me in any way? Also, right now it is just set up as a singlespeed, but I am going to flip the hub and try out fixed, does chainline matter more then?
a good chainline is a good thing because the less perfect it is, the more energy you're losing in friction between links of the chain--when the chain is at an angle, they're rubbing a whole lot more. you can really feel the difference with a straight chainline.
you could try putting spacers into the stack bolts (holding the chainrings to the spider) in order to move the chainring you're using to the right spot.