It is still a marked improvement on the inline four, whose pistons stop and start all at the same time, and is an improvement the inline-six shares with the inline-three it is also the motivation for Yamaha's adoption of the cross-plane crank in its YZF-R1 motorcycle, with four unique piston phases. Inertial torque is typically only of concern in extreme situations, i.e. high reciprocating mass and / or high engine speed. It can however affect low-speed running and flywheel sizing in any case.