Secondary imbalance is largely avoided because the crankshaft has six crank throws arranged in three planes offset at 120°. The result is that the bulk of the secondary forces that are caused by the pistons' deviation from purely sinusoidal motion sum to zero. Specifically, the second-order (twice crank speed) and fourth-order inertial free forces (see engine balance article) sum to zero, but the sixth-order and up are non-zero. This is typically a tiny contribution in most applications, but may be significant with very large displacements, despite the usual and advantageous use of long connecting rods reducing the secondary (second-order and up) oscillation in the piston motion in those applications.