Originally Posted by Dune
Sorry - should have mentioned the brake pedal itself does not appear to be dragging at all. I have cleaned it as well and greased it up and it seems free to move at will when I have the bike parked...
Well that takes some of the possibilities away. Try pulling the rear tire and see if the caliper looks like it is functioning correctly and see if the brake pads have even wear. It would be beneficial to put the bike on the stand and spin the wheel and see if you can recreate the problem as well.
Did the PO say the rear rotor was still warped? When you spin the rear wheel is there a high side on the rotor that drags considerably on the brake pads? Do you see any major movement of the caliper on the pins as the wheel spins?
Hopefully you can pin point the problem