I'd expect a vintage watch's power reserve to weaken over time?, but curious to know what actual results you guys experience. My results - (in general I have not timed them):

movement 352 - stops by morning
movement 501 - still running in the morning
movement 564 - stops by morning

 

Then no conclusions can be made. You need actual facts.
Were they even fully wound?
Service history?

 

The bumper autos like the 35X series are not as efficient as winding the mainspring as full rotor movements so that may have something to do with it. Otherwise, you may have a tired mainspring in both the 352 and 564 but less so in the 501. Or the pivots and bearings are dry and full of friction. Nominally, the 352 has the lowest reserve of those 3 and the 564 the longest, so that may be suggestive of ill health there.

 

Also depends or how active you are especially with the bumpers. Sitting at a desk all day and watching TV will not result in a full wid at bed time
My 351 from 1951 with original (or very old) mainspring has a reserve of 28 hours since it was serviced.

 

I’ve been wearing my 70-year old calibre 355 bumper Omega now for several weeks, 24hours per day. In those two weeks, it has not run down. It was serviced (by me) two years ago, and the mainspring replaced. If I were to decide to wear it only during waking hours, I know very well I could count on it running down and stopping, two or three times per week. Part (I suppose) of the fact that we are in the middle of winter, and my level of activity is reduced. My Rolex Air-King Perpetual Date (52 years old) is also worn 24-hours per day. But it would perk along quite happily being worn only 12 hours per day. Bumper automatics simply do not wind as efficiently as more modern self-winders.

Wearing a watch 24 hours per day doesn’t work for some people. So if you are one of those people, live with your bumper automatic (or any other automatic winder that needs servicing), stopping occasionally.

 

interesting...good to know. I must say, I've enjoyed the little bump from the bumper from time to time...makes me smile...

 

What's the reason for asking that question ? Every vintage mechanical movement behaves differently. Can you elaborate and give scientific relevant data ?

 

While I don't expect a vintage watch to perform as new - I'm new to vintage and just trying to set an expectation of what's acceptable. I just got these and have not had a chance to time the power reserve. i wore them for about half a day put them down that evening and in the morning they had stopped

 

I'm not sure I understand the data presented by the OP. What does "stops by morning" mean exactly? What is the context?

 

Try this. Wind the bumper automatic manually, by turning the winder about 40 to 50 turns. You’ll do the watch no harm. THEN wear it half a day, every day, until it runs down again. And it likely will. When it stops, repeat!

 

alright. makes sense - good test. I guess I'm just use to modern - they'll run for a few days just sitting...

 

Expectation? It looks cool, keeps pretty good time.

What is the time? Look at your iPhone

 

ha ha...exactly! and I thought I was the only one....

 

we can’t tell if you are starting with the watch fully wound or not.

 

Am I an oddball in that I simply wind my watches before putting them on, regardless if they are automatic or not? I simply wind until the crown stops, or if it's an automatic, wind it about the same amount of turns, or more...strap it on, and go about my day. I don't understand why some feel that hand winding an automatic is a no no.

Now, can you use the automatic function as a method to determine if a service is in order, yes, at least according to what my watchmaker advised...hand wind it fully in the morning, strap it on for the day, take it off to sleep, if it's stopped the next morning, a service is absolutely needed.

 

Wearing a bumper automatic for 12-hours, without first winding it manually, is a common phenomenon. The more active a person is, the longer the watch will usually run when removed. But when one is put on in the morning without winding, and it stops after midnight. This indicates that, in 12-hours of wear, the watch is only capable of winding for about a 15 hour run. That is, it winds sufficiently to run it for (say) 12 hours, PLUS an additional reserve of three or four hours. Hence, it is stopped by morning, as a rule. I don’t have a problem with my bumper automatics stopping, as a rule. Unless I wear it on my left wrist! If I wear it on my right wrist, it generally won’t run down. I play a violin, and the right arm is the bowing arm! So no problem!

 

well, one has to keep some things private

But...........if I gotta know the exact time, right now,..............I look at my iPhone, and still have a cool lookin' vintage watch on my wrist.



As a general rule, I have my WM place the micro regulator at dead center and then perform his voodoo to dial in time, then use the micro regulator to tweak for reasonable accuracy, I pay a bit more for this.

There are a handful of my watches that I want absolute precision and I pay for his expertise and time to achieve that in all positions, my A386 is one such example.

 

I think we found the solution to OP's issue...learn the violin and wear them on your right arm!

 

Serviced 285 cal about 36hr after full wind (55-60turns).
561, 564 and even 562 keep ticking easily after 40hr (no main spring replaced in my possession)

 

Works for me!