[huphtur]

That news article may not be entirely correct: https://www.eptc.co/watts-the-deal-with-motors/

[rasz_pl]

This guy analysed a control image - image taken of a KNOWN bike with a vivax motor - and came to a conclusion there is no motor in that picture.

[mrob]

What's more it claims that friction is the biggest source of losses in an electric motor, when it's actually a very minor source of losses. The biggest losses are from resistive heating. See section "Motor Efficiency" at:

http://www.nrcan.gc.ca/energy/products/reference/15297