Flywheel

A flywheel is an assembly consisting of weights that is bolted to an engine crankshaft to provide additional inertia during non-power producing strokes. The flywheel helps to smooth out abrupt movement of the crankshaft during the power stroke. Aftermarket flywheel weights can be purchased for some motorcycles to change the power characteristics of the engine. An engine fitted with a lighter flywheel will be more responsive to throttle input and rev faster – it will also be prone to easier stalling. An engine fitted with a heavier flywheel will be less responsive but will retain its power through inertia of the flywheel and be less prone to stalling. A heavy flywheel is desirable on a trail-bike being used in tight technical situations while a light flywheel is desirable on a motocross bike being run on a wide open track.