Bicycle Drivetrain Analyzer

I stumbled across a great gearing calculator on Observable by Tyson Anderson called the Bicycle Drivetrain Analyzer and added it to Web bicycle resources. It leans heavily on visualization to show any number of drivetrain gear combinations, overlap, and spacing, primed for comparison. Only Shimano groupsets are built-in options, but it also supports manually specifying any kind of cassette or chainring combination.