Should the rotors be turned at the same time new brake pads are installed? I bought a bike just recently and the front disc has some pretty big grooves in it with about 45% brake pad left. I want to replace the current pads but not sure if I should just replace the rotor as well. Does anyone know of any places where I can purchase good rotors at a reasonable price or a shop to have them machined? The bike is a 2002 Ninja 500R with approx. 25,000kms. Any help or advice with brakes would be so helpful! THANKS!