hi guys. I have a trek 8000 with regular shimano lx disdc brakes & there is simply not enough braking power on the rear disc. The brakes were bled not long ago by the shop, I have cleaned the rotor & there is still a milimeter or so on the pads currently in there, yet no stopping power still. I have a new set of sintered pads to fit in but just in case the rotor & pads are contaminating each other somehow I want to clean the rotor. What in your opinion is the best cleaner for rotors?