The bicycle as we know it today, with two similarly sized wheels and a chain drive system, was originally commercialized by John Starley and William Sutton in 1885. And since then, nothing better has been invented in terms of energy efficient travel.
While the energy supplied by the human body to move is relatively low, the human-bicycle duo is undoubtedly the champion of energy performance. As this infgraphic based on data published in the French journal Groupement pour l'Étude des Transports Urbains shows, it is the mode of transport that requires the least energy per kilometer travelled.
Not only does cycling outperform other "artificial" modes of transportation in this area, even electric ones, but it is also more efficient than walking. On average, it requires about half the energy of walking to cover 1 kilometer (although walking becomes more efficient on steep positive gradients). The ratio of energy efficiency to the average speed of the bicycle - nearly 20 km/h - is also very interesting, especially when compared with other motorized modes of transport in dense urban areas, where the speed limit is often 30 km/h.
But what explains such efficiency? Cycling is a weight-bearing activity, meaning that the cyclist's weight is supported by the bike (essentially at the saddle), whereas a walker will have to lift slightly with each step and make an effort to compensate for gravity. In addition, the transmission of power to the wheels via the crankset and chain is a particularly efficient system.
