CACycling

Any number I might give would be explained away as placebo effect or some other smoke and mirrors. When I am in start and stop traffic, acceleration is easier and faster on 18 lbs. of bike than 25 lbs. of bike. Perhaps we should just TELL the racers they are on light bikes. It wouldn't matter and they'd save a bunch of money.

Kneez

This is an excellent idea! I am going to have to try it on myself.

Actually, something a little odd happened with me. The bike I used to ride in the 1980s-1990s was something like 24 pounds. For the era in which I bought it it was on the heavier side of things but lighter than a lot of stuff that was out there. When I bought my current bike last year it seemed heavy to me and even heavier after I bought some stronger wheels. When I actually weighed it, however, I was surprised to learn that it's 21 pounds with empty waterbottle, cage, and frame pump. Who knew?

At any rate, riding a lighter bike is different from riding a heavier bike. Of course, it is not the only difference. Tires, tire pressure, gearing, frame rigidity/flexibility, and how loud the corporate logo decals are (ok, not this one) all make a difference as well.