There’s a huge menu of build options, which you can get a sense of by comparing this test trike with CeCe Balfour’s ICE ...

This one’s simple. For use on small 20″ & 24″ wheeled bikes, Shimano Cues adds a short cage 9/10-speed Shadow derailleur that will still work with up to an 11-39T cassette spread. For 20″ wheels, ...