A relationship with a bicycle can be so. . . personal. The bike has needs, air in its tires, lubricant for its moving parts. The rider also asks the bicycle for things, to be fast, comfortable, light weight. It's a give and take relationship. If you want a rugged, forgiving bicycle you may purchase one made mostly of steel and other heavy materials. If weight reduction is more important, you may opt for a bike made of carbon fiber. But, as I said, there is always a price to be paid. I invite you to check out a blog I came across reading Urban Velo, called Busted Carbon that documents in pictures the price sometimes paid for weight reduction.