WHY DO HARLEY FLYWHEELS TWIST?

The leading causes of excessive run-out are high rpm downshifts, high rpm clutch drops & throttle 'chopping'. The OEM Flywheel/Crankshaft is fit for purpose & will do hundreds of thousands of kilometres/miles with regular maintenance. However, if you want to race, wheelie, or skid your Harley, you may need to upgrade the flywheel set. There is a lot of weight hanging off the left side of the crank & the right side is driving the valve train.