if the generator can be made thinner, to be put instead of the 2-or-3 pedaled gearwheels (5-7cm?), would be fine. And Can be quite larger diameter, and any shap

if the generator can be made thinner, to be put instead of the 2-or-3 pedaled gearwheels (5-7cm?), would be fine. And Can be quite larger diameter, and any shape, it won't rotate