Zero Z-Force Motor Recall


Here’s the press release:

Report Receipt Date: MAR 12, 2014
NHTSA Campaign Number: 14V119000
Potential Number of Units Affected: 94

Manufacturer: Zero Motorcycles Inc.
Zero Motorcycles, Inc. (Zero) is recalling certain model year 2014 Zero SR motorcycles manufactured December 30, 2013, through February 20, 2014, 2014 Zero S motorcycles manufactured December 26, 2013, through February 18, 2014, Zero DS motorcycles manufactured January 24, 2013, through February 4, 2014, and 2014 Zero FX motorcycles manufactured January 14, 2014, through January 27, 2014. Due to a possible manufacturing defect, the motor rotor may contact the stator while riding.
If the rotor contacts the stator, the motor could seize, locking up the rear wheel which could increase the risk of a crash.
Zero will notify owners, and dealers will test the motor and if it fails testing, replace it, free of charge. The recall is expected to begin in April 2014. Owners may contact Zero at 1-888-786-9316 (1-888-RUN-ZERO).
Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to

December, 2013 through February 2014 – all models.  94 bikes.  So, what, 30 bikes a month or so…  interesting sales numbers, and in winter months.  It would look like they changed something in the motor design, since I think they’ve been running that motor since 2012.

Here’s how they describe the motor:



The Z-Force® motor was developed from the ground up by Zero Motorcycles to be highly optimized for efficiency, power and size. With nearly the same weight and volume as competitive brushless motors used in similar applications, the revolutionary Z-Force® motor produces up to 130% more power and 150% more torque. Even more impressive, the compact brushless motor requires no liquid or forced-air cooling. By placing the heat-producing elements towards the outside, where the heat radiates away via aluminum cooling fins, the motor is completely sealed and requires no routine maintenance.

When combined with a Z-Force® power pack, the motor delivers incredible horsepower and breathtaking acceleration. Providing a unique ride quality, the motor produces 100% torque from a standstill for instantaneous throttle response and incredible off-the-line performance.

While sophisticated, the Z-Force® motor is designed to make the ownership experience simple and exhilarating. All extra parts, maintenance concerns and weight have been eliminated to help riders focus on the best part of owning a motorcycle – the ride.

  • Available in two configurations: 75-5 and 75-7
  • Capable of as much as 67 hp and 106 ft-lbs of torque
  • Impressive torque and a broad power band
  • Designed from the ground up by Zero Motorcycles to be the best electric motorcycle motor
  • Efficient, powerful, compact, brushless and sealed
  • Requires no routine maintenance
  • Passively air-cooled requiring no complex cooling systems

Conclusions?  I’ve heard a few people with vested interests suggest to builders that they might consider running the Zero drivertrain and save themselves the hassles of building their own.  I wonder if the recall would have covered them, and if Zero would have replaced the motors…  I wonder what they changed in late 2013.  I wonder if they’re simply going to change it back.  I wonder if it was just a manufacturing defect.

So many questions.

There’s a pretty active thread on the issue on the Electric Motorcycle Forum, here.

EDIT: This word from a Zero owner: “I was told that the problem was that the magnet adhesive was not applied correctly to some motors when they were assembled at the factory.”



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