Defective Wheel Bearings
From Unofficial Zero Manual
Some models suffered from defective wheel bearings.
- Usually these bearings should last 80,000+ miles, but some owners have reported much lower lifetimes (10,000 miles).
- Snapping / clicking / popping sounds. This noise is typically heard when cornering or making sharp turns.
- Grinding when the vehicle is in motion. The noise is normally heard when turning or when there is a shift in load.
- Sharp strike (as if someone struck the wheel with a hammer) accompanied by a grinding sound.
- Related Symptoms
- The noise / vibration will vary depending on the load / resistance applied to the weel.
- It might disappear when the motorbike is on a lift (in this case, using the brake of the damaged wheel could help applying enough resistance for the noise to appear).