A tool that determines the relationship between the number of teeth on the front sprocket (chainring) and the rear cog (driver) of a BMX bicycle drivetrain. It provides a numerical representation of how many times the rear wheel rotates for each rotation of the pedals. For example, a 28-tooth sprocket and a 9-tooth driver yield a ratio of 3.11, meaning the rear wheel turns 3.11 times for every pedal revolution.
Understanding this relationship is essential for BMX riders as it directly impacts acceleration, top speed, and the effort required to perform tricks. Historically, riders adjusted gear ratios based on feel and trial-and-error. The advent of accessible calculation tools allows for a more precise and data-driven approach, enabling riders to optimize drivetrain setup for specific riding styles, terrain, and competitions. This optimization can lead to improved performance and reduced fatigue.