TBM .... the received wisdom is that drilling allows the gasses produced by the pads under heavy braking to dissipate, breaks up the water film on the disc surface in the wet, gives better initial bite, 'self-cleans' the pad surface, helps cool the disc ...... and they look cool 🙂
On the road, my bike discs are drilled but my road car one's aren't.
Never done a back to back comparison as the racer has always had drilled discs.
K
