This one’s a no-brainer. When riding in dense city traffic, you need to concentrate on the road, not on your shifters. With SRAM’s AUTOMATIX two-speed hub, you can focus on your lane, and the hub will change gear automatically for you based on your speed. There’s no shifter, because the centrifugal clutch chooses your gear automatically. It’s a fantastic system for riding around town, with a minimum of terrain changes.