For those of you who do not understand the need to reduce the weight of a tool, try holding a pound of butter at arm's length. Keep your arm parallel to the floor and see how long you can hold it before the pain begins.

I offer this example of how weight of a tool, and a bike is really only a tool, can impact usability. Lighter bikes are faster and more agile, all other things being equal. It is simply a matter of math.

As for body weight? My guess is that a 100 pound woman (or man) will be able to hold the pound of butter just about as long as a three hundred pounder. But that is just a guess.