you know, reading all these weights, and given that my bikes all pretty much weigh about 30 lbs or a bit less, I can only wonder what it must be like to ride a sub-20lb bike. You see often in the roadie section of guys with 16lb bikes....I imagine even a $1500 road bike is under 20 lbs nowadays.
I often wonder what it must be like, and how gearing is affected. I ride in hilly stuff often and I suspect that a 30 granny with a 27 cassette or even a 25 might be doable on a bike that weighs a good 10 lbs less or even 15....
power output vs weight of rider still matters more than weight of bike. 30yrs ago I could go up hills fast and steady, now I go up slow and steady.