Originally Posted by Skipjacks

Drilling holes in the rotor does not give it more surface area.

Assuming the rotor is 1/16th inch thick and you drill a hole that is 1/4 inch wide, the surface area lost will be exactly half of the original surface area of the lost piece.

The 1/4 inch 'hole' have a surface area of 1/10th of 1 inch (double pi r^2 since the missing hole would have 2 sides, thus doubling it's surface area)

So the rotor loses .1 square inch of surface area from the disc...but adds some back as the sides of the new hole

The new hole is .25 inches across with a dept of 1/16th inch. So the sidewall of the hole is .05 inches. (2 pi r = C, C*1/16th equals surface area of the circumference wall)

My 1/4 inch hole and 1/16th inch rotor make it exactly double. A thicker rotor would have more surface area on the new side of the hole, but would have to be 1/8th inch thick to even equal the surface area lost from the hole itself.

MATH FIGHT!!!!!