Recumbents and folders kind of run out of gears when you want to go fast if you use compact road or trekking cranks. Shimano came up with the Capreo cassette/hub design with a 9t small cog. Sunrace makes high quality cassettes and matching hubs with this design.
7075 alloy cassette body
Sealed cartridge bearings
11-speed road compatible
6-bolt rotor mount
(Use only with Sunrace CSS series hubs)