Had a quick check to see if other dedicated threads on this, but nothing I could see. Maybe a useful thread for owners of 3861 Speedmaster, or those considering purchasing.

I had a slight concern last week, when my few weeks old Speedy appeared to lose 10-15 minutes. It had previously been running consistently slightly fast so was a bit shocked by this. Ultimately it was near the end of the power reserve as I had believed that this was within 24 hours of full winding, but in retrospect, I probably misjudged by a day (so, likely circa 48+ hours of winding). Also had used the Chrono function heavily during that period and believe I may have also left it on inadvertently for a few hours, all presumably draining power.

Anyway, I thought I would do a full test to see if I was getting the full stated 50 hours. Long story short, I believe I got just over 64 hours of accurate timekeeping, on a full wind (with no chrono use during that time). It stopped in the early hours so I can't be exact on this. Anyway, very happy with this, especially given the 50 hours stated by Omega (and I would have been happy just to get the 50 hours).

In researching this I did see one useful thread Bought the new 2021 Speedy Hesalite Today (Photo Intensive!) where @thewodg added: [I am very impressed with the 3861 so far. I checked the power reserve, which was actually 65.5 hours. Even better, the watch seemed to continue performing within its specs until at least hour 62 (when I went to bed)]

So, to the point of this post, I would be interested to hear if others have similarly tracked this to share experiences, and as a question, I assume that the power reserve performance will decrease with age, but would be interested to know from others more informed on the subject.

Thanks.

 

There is some discussion on this thread: https://omegaforums.net/threads/questions-about-new-3861.130899/page-2#post-1780550

I checked mine last week, it ran to 64.5 hours. I used the watch tracker app and it kept very good time until right at the end (last two or three hours)

 

Thank you.

 

A couple of weeks ago I got my cal.3861 Speedy. I was disappointed in what I found to be a very limited Power Reserve, 20 hours +/-. I asked our very informed members and the consensus of opinion was that I needed to wind my watch until the crown stopped. Having owned several manual wound watches over the decades I was reluctant to wind it beyond when I started to feel any resistance. Additionally, winding was very stiff. Turns out that within a few days winding became much smoother and less resistance thus 40 winds. Power Reserve is increasing, now 48 to 50 hours. Yesterday a full 40 turns winding and now only "time" will tell how much reserve. I'll let you know.
BTW: Although it's like brand new, it's an excellent timekeeper as it should be

 

Thanks for sharing, I was amazed today/last night how accurate/precise it seems to remain until the very end of the PR. I thought accuracy would have been lost at the end (though, admittedly it was the early hours when it finally gave out, so accuracy may have slipped at very end).

 

After a few days of allowing my watch to stop running after a full winding with my Power Reserve increasing every time. My latest full wind produced a full 63 hours of continuous and accurate running. Needless to say all is well

 

If these are capable of getting 60+ hours why wouldn't Omega let people know that? I can understand a little time over. My 1861 has always got about 50.5 hours instead of the 48 that it's listed as having. But 64 hours when it's listed at 50.....seems very odd to me. But a welcome plus for anyone that gets that much reserve!

 

64.5 for me as well. Just awesome.

 

That's not how a watch works. The main spring is not like a fuel tank that you drain faster if you run the A/C, or have a heavy foot, or carry a lot of crap in the trunk. There is a fixed ratio between main spring unwinding turns and time as measured by the watch. As the spring unwinds, it delivers less and less torque, and when the torque needed to run the watch is larger than what the mainspring delivers at that point, the watch stops. If you are running the chronograph, the watch needs more torque to run, and will stop earlier IF you are running the chronograph at that point. It doesn't matter at all whether you ran the chronograph earlier. There is no way for the mainspring to unwind faster and deliver a higher torque depending in what functions you use. The gearing ratio is what it is.