another noob question..
Isn't it possible that for manual winding watches, the force applied on winding the crown could be higher and irregular which puts more strain on the gears compared to automatic winding of the rotor where the force is more constant and controlled?What this means eventually is that automatic winding wears down the gears slower overall compared to manual winding.
Noob question pertaining manual winding as I don't own one yet:-
Will there be more wear and tear for manual winding compare to automatic winding (with occasionally manual wind)?
Answers is no. Automatic watch typically has more wear and tear compared to manual watches.
Automatic watches will continue to wind when worn and needs a mainspring clutch to avoid overwinding when power reserve is full
A wound up manual watch will just run its course until the end of its power reserve. You just have to make sure not to overwind it manually to avoid damage.
With less parts and less complicated, they are easier to service too (and should be relatively cheaper).
Modern day hand-wound mechanical watches are made from some of the finest materials and can surely deal with regular usage and in this case, how it is meant to be used; winding the crown with hand.
Even the simplest hand-wound pocket watches would have the stem winding the smaller winding gear to the larger ratchet gear to reduce torque and allow minimal strength to wind the mainspring. The transfer of the irregular force that you refer to would be minimal to the rest of the watch mainspring or gear-train (hour/minutes/second) gear, hence unlikely wear from just winding the watch manually.
Check out watches like Glashutte Original's Senator Chronometer where they use a more elaborate planetary gear system for their winding and power reserve. It is silky smooooth.... Other fine examples are any of the standard Piaget hand-movements.
If any wear, it would be the Keyless-Works and that may be due to poor assembly or trying to wind it when worn on the wrist (angular/lateral forces that may damage the stem, hence advice is always take off the watch when winding manually)
Also, the force is not constant and controlled in an automatic watch, especially when worn, because we engage in different types activities and different patterns of lifestyle throughout the day.
It would be constant however, if the watch is strapped to a watch winder.
But would this wear the parts less than a manual watch? again the answer is no due to the constantly rotating rotor despite the mainspring is full. It's like a car accelerating and applying breaks in the same time (not a perfect analogy, but close)
In any case, with modern and improved materials nowadays, the difference between the 2 is very minimal. As long as the watches are not misused, and serviced regularly (within average of 5 years), it should outlast the owner. Even the most humble ETA/Valjoux can last longer than most of us here, if serviced and maintained well.
