I've never seen the point to really light bikes. I can understand that it's a project or whatnot, but really, why? Is there a serious difference in losing that 500g, or is it more of an ego thing?
. For example, my bike should weigh about 12.5, but it's currently at about 15 according to my bathroom scales, and I don't care. It's not the bike, it's how you ride it!