Difference between revisions of "Motor Whirring"

Latest revision as of 20:45, 31 March 2020

The motor on 2013+ models makes a white noise sound at very slow speeds when rotated (by the wheels or shaft).

This is also described as a "whirring sound".

This is alluded to by the term "cogging".

This is normal as long as it sounds like white noise and occurs as described below.

Video Guide

• Strange noise Zero DS 2017 provides a reference for comparison:

Related Confirming Symptoms

• The noise should only occur while the motor is rotated by external input (pushing the bike around or rotating the shaft).
• The noise should not while under power (when the motor is driving its own rotation).
• The bike should gently resist being pushed while the noise is audible.

Causes

• The direct cause is the controller applying a white noise field to the motor at very slow speeds.
• At least one connected battery's contactor must have been engaged for this to occur.

  This can occur while keyed on, or while charging.

Effects

• There are no detrimental effects, when the sound occurs by design.
• The purpose is for the controller to detect and maintain precise knowledge of the motor's rotor angle.
• This ensures that, if the throttle demands operation, the controller will apply the field correctly to the rotor.
• You may infer that at least one contactor is engaged to power the controller.
• If the bike is keyed on, you may infer that the motorcycle should be ready to drive.

  (aside from the kickstand and kill switch safety interlocks).