&gt; But I had to laugh out loud when I saw a video bikes crashing yet the back wheel was still spinning.<p>Was that the old chestnut with Hesjedal&#x27;s crash? Com on, that&#x27;s just nonsense. The wheel was spinning after the crash from inertia — that is not only plausible, it&#x27;s entirely expected, and the case in major crashes all the time. There&#x27;s absolutely <i>no</i> reason to believe that this was caused by a motor.<p>Besides most of these motors (including the one just found) spin the <i>pedals</i>. So if the pedals continued rotating after the crash, you&#x27;d have a point. The ones that propel the wheels directly with neodymium magnets cost like 50k a wheel and are probably a lot less common to begin with, if they&#x27;re even being used at all.