Zero Motorcycles, Inc. (Zero Motorcycles) is recalling certain model year 2012 S and DS motorcycles. These motorcycles are equipped with a motor encoder position signal that may drift over the extended use of the motorcycle. If the signal drifts outside of the given parameters, the motor controller may shut off, resulting in the motorcycle inadvertently losing power. A loss of power could lead to a crash and potential injury or death of the rider. Zero Motorcycles will notify owners, and dealers will reprogram the motorcycle's motor controller free of charge. The safety recall is expected to begin on September 24, 2012. Owners may contact Zero Motorcycles, Inc. at 1-888-786-9376. Customers may contact The National Highway Traffic Safety Administration's Vehicle Safety Hotline at 1-888-327-4236 (TTY: 1-800-424-9153); or go to www.safercar.gov.