Bigger cylinders, more mass. There is an ideal balance between bore size/stroke/piston speed/friction, and Honda thinks it is close to the RC45's size. I think they just added another cylinder of the same size, and have a counterbalancer to offset the unbalance. Two cylinders up into the frame where narrowness counts, three below.
If the bigger cylinders worked, Harley's would be rocketships, but that aint the case.
If the bigger cylinders worked, Harley's would be rocketships, but that aint the case.