I need some explanation and diagrams on bike hubs: freehubs, internal gear hubs, whatever you have.
I am planning to use them to have a variable speed drive on a windmill.
Check these other questions to understand the situation:
Redesigning windmills to use screw pumps
How to design a screw pump?
Is there any way to make them switch automatically?
I want my system to maximize the torque when the wind blows at less than 10 km/h and to minimize it when it is over 40 km/h.
I think I can use something similar to bike hubs to control the drive from the floor, at the base of the windmill, with a cable.