Things I am working on
Gearing on a bicycle enables the rider to traverse differing terrain while maintaining a comfortable pedaling speed, known as “Cadence”, and road speed. For instance, a cyclist with just one gear, riding on flat terrain at 20 mph and pedaling at 90 RPM would have to slow their pedaling speed to just 45 RPM while riding uphill at 10 MPH. Not only is pedaling at 45 RPM going uphill difficult, it also puts excessive stress on the rider’s body and is inefficient; most people’s optimal pedaling speed is 90RPM (Neptune, Journal of Biomechanics 409-415). Thus, it is desirable to have a set of gear ratios to use while traversing varying terrain.
The race for market share in the world of cycling while trying to meet this need has driven growth from bicycles with 10 speeds in 1983 to cycles with 20+ speeds in 2015. This level of gearing requires narrower chains and higher precision shifting mechanisms, thus adding cost and complexity to the machines. It is interesting to note that while the number of gears on a racing bike has steadily increased, the gearing range hasn’t. This has resulted in redundant gear ratios throughout the available range on most bikes. New drivetrains are now placing an emphasis on simplicity by including fewer gears in total while providing a similar number of unique gear ratios. To understand how many gears are truly needed, the author analyzed gear usage during rides on a variety of terrain.