Originally Posted by
torque cyclist
if I have the option to have a strong upper body and go about 1mph slower, then I will take that over being a twig.
I'd probably agree with you, between those choices.
The calculator isn't that sophisticated. The 50 pounds could be anywhere, even on the bike frame, and it would give the same result. It just illustrates that 50 more pounds at a moderate effort does make a significant difference in speed, even on a perfectly flat road.