For the sake of illustration, and I'm not by any means an expert in frames or components, but if I'm looking at two frames - one weighing 5 lbs and the other 2 lbs, that is a 3 pound difference.

I lost that much (3 lbs) the first two weeks I got serious about my health and state of fitness.

For a competitive racer or Olympic class athlete 3lbs in the frame might be critical, but for most of us it should be the least of our worries.

There's just more to it than frame weight.