SUNTECH INNOVATIONS BALANCER
Several years ago, I tried one of Suntech's engine sprocket-mounted balancers. They are simple devices, basically a steel disc with a mercury-filled ring on the outside edge. When the motorcycle is running, engine imbalances force the mercury to the point in the ring where it needs to be to counter the imbalance, thereby reducing vibrations. Installation on my Sportster took less than an hour; the balancer just bolts to the face of the motor sprocket. I found that the vibration reduction effect was small but definitely noticeable. Suntech Innovations also sells active balancers for clutches, wheels, and even flywheels, but I haven't tried any of those myself.
These Sun-Tech balancers also helped lose some
the vibrations from the drivetrain.
