回复：自行车速度表误差 is dependent of the tire index no one puts in at sta

That is the travel distance for each revolution of the bike tire at normal pressure and normal load in milimeters....However I can not relate this incidence to the Honda speedometer inaccuracy issue lately.  I heard of this issue quite a few years back and everybody does it; with Porsche the most inaccurate. I also heard some people saying more performance car makers push this speedometer inacuracy to the limit to benefit their on-paper performance numbers.....