And you've reduced the swept area and reduced braking effectiveness in the process. Ah but it's all about fashion is it not.
Wave rotors have less
surface area than a conventional rotor of the same diameter, yes. But, my understanding is that the effective radius of the disc is at the centre of pressure of the pads, which is constant for a given caliper position regardless of disc geometry (assuming the full face of the pads is swept). A wave disc of a given size has the same
effective radius as the full disc of the same size. So not less effective braking. (But not more effective either).
Any improvement in braking will come from the face of the pad being kept cleaner or from the cooler running disc.
Additionally, less surface area = less material which means a wave rotor should be lighter. That's a good thing, especially so considering that this is unsprung weight.
But over-riding all that, the most important reason for going to a wave rotor is this: They do look cool
.
