the governor can be thwarted if you search through all the discussions.
I've actually turned off the governor and found the motor still tops out at around 20 MPH, simply due to the counter EMF. This is actually good engineering on BionX's part, as motors tend to run at optimal efficiency at around 80% peak RPM if at full load, meaning that the motor is optimized to operate at speeds between 15-20 MPH.