He doesn't know what he's talking about, brakes sensors/cut outs are there to protect the controller from frying. They have no effect on the motor.Thanks for your interest guys. I'm having a bike mechanic do this because I cut my finger. It will use 180mm rotor as you said. But he did not advise me to use the brake sensors. He said after a few months it would cause problems with the engine. Is this true?(I told him to put it on anyway because I want to use my own brake levers.)
Only one sensor /cut out is needed so fit it to the rear brake.