The Castro Duo is designed for one simple purpose, to get you and your stuff from where you are to where you’re going. It has only two speeds — one for flats and one for hills. Automatic shifting with the SRAM Automatix two-speed hub and a coaster brake means there are no messy cables. The integrated rack offers extra stable load carrying with clean styling. Read more here. http://www.ternbicycles.com/bikes/castro-duo