Originally Posted by
chucky
The mechanical coupler will still need to rotate in order to maintain alignment...which will create drag (and probably more than a well made rotor). No matter where you draw the interface there will never be a perfect decoupling, might as well make it electrical.
I can think of half a dozen ways to do the engagement that have no moving part of the clutch rotating when disengaged, and which have zero drag. And that's without thinking hard; there are surely others. I still don't think it's a good idea, but not for the 'it doesn't work' reason. The point of a dynohub is simplicity and reliability. Adding moving parts rarely enhances either of those goals.