Or a motor hidden in a bike frame: https://www.popularmechanics.com/adventure/sports/a19219/professional-cyclist-caught-cheating-with-a-motor-in-her-bike/ https

Or a motor hidden in a bike frame: https://www.popularmechanics.com/adventure/sports/a19219/professional-cyclist-caught-cheating-with-a-motor-in-her-bike/ https://www.popularmechanics.com/adventure/sports/a19219/pro...