Eli5: Why do bicycle disk breaks have “%” and “V”s stamped through them. Is this the most efficient way of displacing heat / reducing cost ( materials ) or does it just look cool?

Question

Eli5: Why do bicycle disk breaks have “%” and “V”s stamped through them. Is this the most efficient way of displacing heat / reducing cost ( materials ) or does it just look cool?

In: Engineering

Answer 1

Makes the disk break lighter and aerodynamic from cross winds.

Also improves breaking in wet conditions as the water gets pushed through instead of maintaining surface tension and impressing breaking