Originally Posted by makeinu
hmmm, omega=V/(2*pi*R), no?
No. omega=V/R. Let T be the period of rotation, then omega = 2*pi/T. V=2*pi*R/T, divide both sides of the equation by R, and you get V/R = 2*pi/T = omega.
Originally Posted by makeinu
Also, you have to remember that it's only 108% (edit 200%)of the energy for the wheel, but the energy put into the wheel is only part of the total energy required to move the bike.
I haven't forgotten that. The analysis seeks to give you a feel for the impact of rotating vs non-rotating mass. Maybe we are agreeing that the mass of the complete package, your M, which really has to include the bike and the payload (rider and any junk they are carrying) swamps everything else.