One of the first lessons you learn in physics is to always ask ma, she'll know. Ok so not-so-funny physics humor aside no matter what, the force you must excerpt to move a bicycle (or anything) is always going to be Force = Mass x Acceleration (F=MA see, there's ma
).
In this case the mass is going to be rider plus bike going your desired speed, acceleration in physics can be a constant speed. So now its easy to see that if the total mass goes down less force will be required to move it. As pointed out before its a lot cheaper for the rider to lose a pound than it is for the bike to loose a pound.
Now this equation only works on flat ground. Should a slope be involved the equation gets much more complex as we'll need to know the degree of the slope, the coefficient of friction, and the ******ing force due to gravity. After all this is figured out it will only confirm what we already know, more mass = more force to move be it flat frictionless ground or up a hill factoring gravity and friction.
So that pretty much puts an end to any type of argument over this. Less weight will always equal less energy output therefor making it easier to ride no matter how marginal it may be.
Bau