Accuracy question from a first time Rolex owner (GMT II C brand new)

[Kallagtunet]

Yes finally gotten myself a brand new GMT II C :-D
Very happy with the look and feel and happy to finally being a Rolex owner after a long series of radio controlled g-shocks…

One question to the experts from a newcomer on mechanical movements.
I register that the accuracy of the watch varies quite a lot through the day. In high activity periods with for example running and other exercise the watch can gain as much 15 - 20 seconds in in 2 – 3 hours period. In quiet periods for example during sleep at night (have the watch on 24/7) it slows down maybe 15 seconds trough the night.

Is this normal behavior to have such big differences in accuracy depending on activity level?

I understand that it is a very complicated mechanical instrument (and that a radio controlled G-shock will always will have a upper hand with regards to accuracy… :-D) but seeing watch reviews where they measure differences accuracy in various positions of the watch my variations seems large?

On an average 24 hour period the watch gain anywhere between 0-5 to 20 – 25 seconds dependent on activity level (this based on a 8 days of use).

[dardeca]

That is not normal.

[Brushpup]

What is normal and within COSC stds is minus four to plus six seconds per day. Give it a week ir two and then average it over a week minimum and then see.

[Lagunatic]

you got a lemon. mine is -3 seconds every 24 hours.

[Watchmutt]

Are you comparing it to a consistent source?

[Kyu]

Congrats !

As for the accuracy u should give it a week
20sec diff is not normal lol but check the min diff also

[gregdolley]

Wow. No that's not normal. My first two Rolexes (a DJ and a DD) were +5 sec/day. My current watch (a new Daytona) is almost spot on, gaining only 14 seconds over 49 days! And that's with the chrono running sometimes - I've noticed it gains more time when the chrono is active; if it's off all the time, the watch seems to gain only about 1/8th of a second per day.

The variations in the accuracy of your watch is what concerns me. It should be consistent throughout the day no matter what you're doing. It may not be as accurate as a quartz movement, but it still should not have such wide variations that you describe. +6 sec/day is the max for a COSC certified watch.

I would definitely have it looked at...

[mmmk604]

I get about +4s...

[How]

My SubC +1s per day.

[GradyPhilpott]

Use time.gov as a reference and you can't go wrong. (I see you're in Norway, so I linked to the UTC mode.) Even radio-controlled clocks and watches can be way off in just a matter of hours because some manufacturers put the cheapest movement they can in a clock that's designed to update with an atomic clock every four hours.

I have a Sharp that's like that. It will get you to work on time, but forget it as a reference.

I have never experienced your situation with my Rolex watches, but mine have consistently gained time over the first year at which time I have them regulated and then they pretty much stay within COSC (-4/+6 sec./day), except for my DJ, which I dropped.

Check the watch about every 24 hours and give it at least 5 days before you make a judgement.

A regulation can be done in short order and under warranty for the first two years, so don't lose any sleep over it.

[Ck8]

Originally Posted by Kallagtunet

Yes finally gotten myself a brand new GMT II C :-D
Very happy with the look and feel and happy to finally being a Rolex owner after a long series of radio controlled g-shocks…

One question to the experts from a newcomer on mechanical movements.
I register that the accuracy of the watch varies quite a lot through the day. In high activity periods with for example running and other exercise the watch can gain as much 15 - 20 seconds in in 2 – 3 hours period. In quiet periods for example during sleep at night (have the watch on 24/7) it slows down maybe 15 seconds trough the night.

Is this normal behavior to have such big differences in accuracy depending on activity level?

I understand that it is a very complicated mechanical instrument (and that a radio controlled G-shock will always will have a upper hand with regards to accuracy… :-D) but seeing watch reviews where they measure differences accuracy in various positions of the watch my variations seems large?

On an average 24 hour period the watch gain anywhere between 0-5 to 20 – 25 seconds dependent on activity level (this based on a 8 days of use).

If you let it run in the breaking in period, keep a record of the gains or loses with your normal wear then you can send it back to RSC to regulate it. As long as your watch has a consistant amount either gains or loses then the RSC can do the adjustment. I have had all my Rolex regulated in the past and I can truly say they have been spot on day in day out.

[James M]

Mines +6 at the moment, was higher then I changed to the crown up resting position.

[caryyee]

If it's brand new, give it a week or so to bed in, and then check it again. But yes, that much of a diff in a 2-3 block seems unusual. Mine is consistent +2 secs a day (not sure what the variation is during high activity periods (I teach and also participate in group fitness classes daily)), but in any given 24hr period, it's +2 secs.

[Kallagtunet]

Thanks for the responses. The ting that worries me is the variance dependent on activity level I can not see how that can be handled through a general adjustment for speed. I will let it settle in one more week. I have used the clock at my PC at home and work as reference. Will use the link provided above to take the potential source variations away.

[Grissom]

Originally Posted by Kallagtunet

Thanks for the responses. The ting that worries me is the variance dependent on activity level I can not see how that can be handled through a general adjustment for speed. I will let it settle in one more week. I have used the clock at my PC at home and work as reference. Will use the link provided above to take the potential source variations away.

I have never experienced that......none of my watches have shown that their accuracy is dependent on my personal activity level. I would recommend that you have it looked at.

[Brenngun]

Dumb question but gotta ask. Did you wind it a full 40 revolutiions of the crown? OK having said that ...... break in period or not it's accuracy should not be affected by a specific activity other than complete stillness.

[Kallagtunet]

Originally Posted by Brenngun

Dumb question but gotta ask. Did you wind it a full 40 revolutiions of the crown? OK having said that ...... break in period or not it's accuracy should not be affected by a specific activity other than complete stillness.

I have not. But the AD said that they did while at the same time they adjusted the bracelet. I have done now to be on the sure side and I have will use only the time.gov for futher checks to be sure.. I will keep you posted and hope that it is not a lemon on my arm (it looks goood thoug...)...

[Kallagtunet]

Have now been excluding potential other explanations? Have winded it full 40 + have timed in only using time.gov and still the same. Regular office level activates it gains 6-8 seconds per day. A training session of 45 minutes of running (not very fast I'm not that fit) it gains 7 - 8 seconds in the short time of exercise where the watch is in more movement.

I.E it seems like I have (very a good looking) lemon on my arm…

Anyone that knows mechanical movements that can explain how this can happen? And what can be done to it?

I will take it to the AD next week, but do not look forward to be parted with my watch for a repair after being a first time in my life Rolex owner for less than 2 weeks! I would ideally want a new one or at least a loaner while it is at repair. What can I expect?

[globalmedia33]

My Sub C gain 2sec. in a month.

[Kallagtunet]

Originally Posted by globalmedia33

My Sub C gain 2sec. in a month.

You are not helping a lot here

[James M]

+2 a month???

[Psmith]

Originally Posted by James M

+2 a month???

My Exp II 216570 (3187 movement) averaged at -6 /month

If I had consistently rested it dial up at night I expect it would have been dead on

[James M]

Originally Posted by Psmith

My Exp II 216570 (3187 movement) averaged at -6 /month

If I had consistently rested it dial up at night I expect it would have been dead on

That's great, wish mine was that accurate.

As it is its just falling within COSC so as long as it stays that way I'm happy.

[padi56]

Originally Posted by James M

That's great, wish mine was that accurate.

As it is its just falling within COSC so as long as it stays that way I'm happy.

You guys make me smile with this accuracy stuff even at the bottom of the scale a modern day Rolex is 99.994% accurate.And seeing that there are 86400 seconds in 24 hours for any mechanical watch to perform consistent to this standard is quite a mechanical marvel.My own 5513 from the latter part of the 70s last set it then,just checked its gained 0.559999999 of a second in 33 years but again a could live on fantasy island.

[James M]

Originally Posted by padi56

You guys make me smile with this accuracy stuff even at the bottom of the scale a modern day Rolex is 99.994% accurate.And seeing that there are 86400 seconds in 24 hours for any mechanical watch to perform consistent to this standard is quite a mechanical marvel.My own 5513 from the latter part of the 70s last set it then,just checked its gained 0.559999999 of a second in 33 years but again a could live on fantasy island.

Agreed I think it's pretty amazing that a mechanical watch can be -+30 a day so a few seconds is no big deal.

Not being spot doesn't detract from my enjoyment of the watch as long as its consistent but being as close to spot on is a bonus.

A wide variation such as the OP is getting would worry me as it would seem to indicate a problem.

[Psmith]

Originally Posted by James M

That's great, wish mine was that accurate.

As it is its just falling within COSC so as long as it stays that way I'm happy.

Me too...

Usually I find that mech watches run a bit fast, but as long as it is within COSC and consistent then I'm happy

The Exp II was a bit of an exception

[jagwap]

You said you were using your home and work computers to time it.

Any chance your work and home computers are 15-20 seconds different? It would be just poor luck if this turned out to be the problem. But your watch may be fine.

[Kallagtunet]

Originally Posted by jagwap

You said you were using your home and work computers to time it.

Any chance your work and home computers are 15-20 seconds different? It would be just poor luck if this turned out to be the problem. But your watch may be fine.

As said in earlier post now using gov.time site both at work and at home. Same probem with speed variance based on activity level...

[nauticajoe]

-4/+6 is the norm. Outside of those parameters......it's not normal.

[Kallagtunet]

Originally Posted by nauticajoe

-4/+6 is the norm. Outside of those parameters......it's not normal.

Yes understanding that. Anyone have an explanation on why 45 min of running can increasé the gain rate so sigificantly? Gaining 8 sec in such short time adding seems strange. There must be an mechaical explanation to the large variance of accuracy dependent on the activity level?