I have heard that micro rotors are not very efficient at winding due to lacking the weight of a full sized rotor. In some ways I can see how this makes sense, in other ways I can't.
Stands to reason there is less leverage in hte small rotor to wind the mainspring ... but good engineering, excellent bearings, etc. can offset those disadvantages.
Yes, of course if you have a bigger diameter, and the mass is further outside, this helps. But, I mean, the heavyweight metal is just at the outside then, and the micro rotor is usually totally out of gold, platinum or tungsten! Also, the bearing is essen...
Micro rotors are way less efficient at winding than a full sized rotor all things being equal. And many micro rotors don’t fully wind the watch. In terms of material anything that’s not platinum or tungsten is likely too light for a fully effective micro ...
My understanding is that all things being equal (eg quality of manufacturing) micro rotors are less efficient than full sized rotors. Where they outperform is that they allow to make the watch thinner by saving one “level” if I may say it so, similar to t...
…a larger diameter rotor harvests more energy per spin. Micro rotors may spin as fast, but they aren’t developing the same amount of torque as the same metal casted into a 3/4 or full rotor