The measure of a bicycle’s gearing expresses the relationship between the number of teeth on the chainring (front gear) and the number of teeth on the cog (rear gear). This ratio is determined by dividing the number of teeth on the chainring by the number of teeth on the cog. For instance, a chainring with 48 teeth and a cog with 12 teeth yields a ratio of 4:1 (48/12 = 4). This value provides an indication of how many times the rear wheel rotates for each complete rotation of the pedals.
Understanding gearing is crucial for optimizing cycling performance. A higher ratio, such as 4:1, generally indicates a harder gear, suitable for high speeds or downhill riding, as it requires more force to pedal but covers more distance per pedal stroke. Conversely, a lower ratio provides easier pedaling, ideal for climbing hills or starting from a standstill. Historically, cyclists relied on fixed gears. The development of derailleurs and multiple gears revolutionized cycling, allowing riders to adapt to various terrains and maintain a more consistent cadence, ultimately enhancing efficiency and comfort.