Unless the ESC has the ability to reverse rotation, the only way to run a brushless sensored motor reverse is to a) remove the sensor wire then b) switch the A and C wires. This will reverse the motor but you will be running not sensored. Which speed control model exactly and why do you want to reverse?

If its this one

http://www.hobbyking.com/hobbyking/s...approved_.html


Then you can use these instructions to reverse rotation keeping the sensor intact. Hook up motor wires as normal. Looks like you need the programming box however to do this.

http://www.hobbyking.com/hobbyking/s...X365809X14.pdf