Hi All
In August last year I bought a new Speedmaster Pro Moon Watch and since then it's been running consistently around +1.5 to 2.0spd, which was great. Over the last week or so this has changed to +11spd, now I know this is still in spec, (just) but I can't recall doing anything different so why might this change so dramatically over a short space of time?
Secondly is there a known degree of positional regulation to be had with this movement? I know Rolex used to issue some positional regulation instruction with some of their movements.
Or might it just need regulating? I assume this isn't fast enough to be caused be any magnetic effects?
Cheers

 

Hi Matt,

The specs for daily average rate (measured over only 3 positions) for the 1861 is from -1 to +11 seconds. Along with that, the Delta (difference between the fastest and slowest positions measured, again only 3) can vary up to 15 seconds at full wind, and then 20 seconds 24 hours after fully winding.

For reference the 3 positions checked are dial up (CH), crown down (9H), and crown left (6H).

Just to unpack this a bit, if your watch is running say +1 dial up, at full wind it could be running 15 seconds different in the other 2 positions measured and still be in spec. So just to keep it simple and use positive numbers only, it could be running as fast as +16 when in the crown down position. After 24 hours it could be running +21 in the crown down position, and still be in spec.

Now keep in mind your watch is in far more than 3 positions during the day, and anything outside of those 3 they don't even check. It's possible that the timing is even worse in those other positions.

So my first piece of advice is to wind the watch every day if you are not already doing so. Next I would try to find a position that helps it keep time better when it's not on your wrist. As much as people want to keep posting that old Rolex thing that tells you what position to store your watch in to make it gain or lose, there is no standard. Every watch is different, so to find one that will slow it down you need to experiment a bit.

Now why the change? Well despite what people might say, I have seen magnetism cause smallish gains in watches. However I think the smallest I've ever seen is maybe 45 seconds a day, s not as small as this is.

Has the watch received a knock of any kind? A knock may move the regulator if it's one that is not particularly tight. Are you measuring it against the same standard you were before, and is that standard accurate? Have your wearing patterns changed, like being on vacation for example so you are not doing the same things you normally would?

I would make sure you are winding it every day, wearing it the same as you always have etc., before making any changes to the regulation of the watch.

Hope this helps.

Cheers, Al

 

Hi Al

Thanks for the very full and informative answer. I've been using the 'Time.is' site for checking the time but also an app called 'watch tracker'.
I wind the watch fully each morning at pretty much the same time, as I read somewhere it helped with accuracy? As for a knock, I can't recall anything but I have been wearing it pretty much 24/7 since I bought it, so I may have. Interestingly I have taken it off the last few nights and rested it crown up. Normally if I don't wear it for a day it sits dial up. I'll go back to that sort of routine and see what happens.
Thanks again for the reply
Matt.

 

Hi Matt,

Al serviced my 1968 861 Speedmaster in August of 2013 and he know his stuff. I do notice small variations in the amount of timed gained or loss depending on the position of my watch at night. By trial and error you can see which position works best for your watch.

If I lay mine dial up it runs fast and gains about 5-6 seconds an night. I found that for mine, on the bracelet with the pushes and crown up the watch is spot on, maybe gaining a second a day. When left crown up in the evening I can go a week or two without resetting the watch and I'm obsessive about having the correct time. I believe this is a testament to Al's workmanship and his knowledge.

Like Al said, fully wind it and play around with different positions. Unless there is an issue you will probably stumble on the combination of positions that works best for your watch.