More about shorter cranks:
http://www.applemanbicycles.com/resources/
https://www.researchgate.net/publication/11923708_Determinants_of_maximal_cycling_power_Crank_length_pedaling_rate_and_pedal_speed
Another bike publication has a good article about this, posted Set/22.
Good questions. Will send them to Hope.
It is harder to find 104/64 to go bellow 30t.
Not sure this can handle agressive ridding too, but can be an option for urban. I will try it on a trike.
https://a.aliexpress.com/_mL2nR42
