What is Rotational Inertia?
Inertia is a “resistance to a change of motion”. The more inertia an object has, the less it responds to being accelerated or pushed. You are no doubt aware that, all other things being equal, that a heavier bike will accelerate down a drag strip slower than a lighter bike. The more weight or mass in an object, the less it responds to being accelerated or pushed. Rotational inertia is a resistance to change of rotation. The more rotational inertia designed into an object, the less it responds to being spun up. An engines flywheel is designed to use this principle to slow or accelerate an engines throttle response depending both on its weight and how far out from the centre the weight is placed. The further out from the centre the weight of a spinning object is placed the greater inertia it creates. This is particularly important on Supersport bikes as the FIM Supersport rules prevent modifications to the crank. You cannot then modify the crank for quicker throttle response to make up f
