World Bicycle Relief explains that its Buffalo bicycles are designed to be “extremely durable to serve the needs of people who travel long distances over rugged terrain with heavy cargo in some of the world’s harshest environments.” With that in mind, simplicity and ruggedness are absolutely critical, and the redundant chain system is designed to provide a high/low gear solution that involves as few breakable, externally mounted parts as possible. These bikes are being delivered to places that don’t have access to bicycle shops or spare part overnighting, so making something that’s as tough and easy to repair as possible is an essential part of WBR’s job.
It’s an interesting design – and patented. If WBR really wants to have a big impact in the global South, they should release design with open, inclusive licensing so that entrepreneurs in the global South can manufacture it locally, without relying on imported hubs.
The article only mentions US patent. Hopefully that is mainly to preserve their IP in the US and later perhaps few other high income countries.
Many in the global south will come up with diy knockoffs in an eye blink if WBR tries to make it too expensive to manufacture locally.