Wolf Tooth Tanpan 11-Speed Conversion. The Tanpan brings the range and security of Shimano mountain rear derailleurs to Shimano-equipped drop-bar bicycles. This means a greater gearing range for bigger adventures better chain security for rough terrain and lighter weight and reduced complexity for the daily commute. In order to deliver these benefits the Tanpan amplifies road shifter cable pull to allow for seamless communication with mountain derailleurs. The result is ideal for riders looking to convert their road gravel cyclocross or commuter bike to the simplicity and light weight of a single chainring.