This is a library of code which supplies the necessary pieces to create a bike gear calculator which will work for fixed gear, internal hub gear, and deraileur gear bikes. It can calculate gear-inches, meters of development and gain ratios. Speed at RPM is also incuded. For fixed gear bikes the number of skid patches is also calculated. Data for wheel sizes, internal gear-ratios, common gear cluster configurations and crank lengths are also included. I did this project with an eye towards learning cljc/reader-conditionals and how to use spec for all it’s various uses. This is still evolving.