GMT IIc - RANT

[whw]

Bought my first ever Rolex, a beautiful SS GMT IIc in May this year. Wrote about it here: http://www.rolexforums.com/showthread.php?t=46876

After about 4 months of use, the watch was consistently about 4.5-5 seconds slow per day. So I took it to the Rolex Service Centre to get it regulated. After that it was about 1.5 seconds slow per day, which is alright with me. But would have preferred it to be faster instead of slower. I don't mind if the watch is slightly fast, but it gets to me if its slower.

2 days ago the watch was behind by about 45 seconds, so I resynchronised the watch with time.nist.gov. At the end of the day the watch was slow by 1.5 seconds. Which is alright. Note that I wore the watch for the whole day after resynchronising it earlier in the morning. So the watch is surely fully wound up at that stage. At the end of the day I took it off to sleep. The next morning (ie this morning), the watch is slow by 5 whole seconds (ie. it lost another 3.5 seconds during the night (about 10 hour period).

I notice (in the past) that the watch stays consistent if I wear it for the whole day, but not wearing it (or even putting it on a winder) will cause the watch to slow down by more that the usual rate. So the power reserve somehow is not able to keep the watch running consistently even for a 24 hour period of inactivity.

I notice that if I wear it the whole day, before I take off my watch to sleep, it picks up a 1-2 seconds. So the net variance is about 1.5 seconds per day.

Now, don't get me wrong. I love this watch tremendously. And a few seconds off per day is really nothing and acceptable under COSC. BUT when I compare it to my Omega Seamaster GMT (that uses an ETA-2892), the Omega trumps the Rolex in terms of accuracy. My Omega is consistently fast 3 seconds per day. I can leave the watch inactive for 40 hours and it still maintains the +3 seconds accuracy. And the end of a whole day of use it is not faster or slower that what it should be. It is by far the most consistent watch is my small collection.

Any comments or feedback?

[mickeydainish]

Hey man... tah for your comments..... there are plenty guys around who know what they are talking about... I am sure they will chime in soon.... Otherwise that does seem a little off to me..... :-)

[mldaytona]

Could you please post a pic or two of your Speedmaster GMT? Thanks so much in advance. I am sorry I can't help you on the accuracy issue coz I wear my Rolex primarily for show.....when I need up to nanosecond accuracy, I have a little Casio Baby-G tucked in my jeans coin pocket.

[Art161]

It might be that I am not understanding something here. You say you set the time on the watch and then wore it all day, and conclude that it must be fully wound at that point. Did you wind the watch for 40-45 360 degree turns of the winding crown when you set the time? When you wear the watch and provide "normal" movement of your wrist, you are just about maintaining the power reserve at the level it was when you starting wearing it.

Let's look at it this way. Say the watch has stopped. You can't just start wearing it and expect it to build up much of a power reserve, if any reserve at all. If it is at half the reserve when you start wearing it, it will probably be at approximately half reserve when you take it off.

Wearing the watch with "normal" movement of your wrist simply maintains the power reserve at approximately what it was when you put it on.

I hope this helps.

[Z-Sub]

If it is still slow and unsteady, you should bring it back for another service and have them adjust it so it is a bit faster than slower. it's simple adjustment by Rolex. It would bother me very much as well.

[ayecarumba]

I had heard from several friends with various collections (Brietling, Omegas, etc..) that their Rolexes kept the worst time from their collections.

I have found that my GMT IIC I purchased in July from my AD runs consistently -7secs slow/day. That's well outside COSC of -4/+6.

http://rolexforums.com/showthread.php?t=51468a

I guess my choices are to accept the -7 secs or send back to RSC..any thoughts?

[whw]

Originally Posted by mldaytona

Could you please post a pic or two of your Speedmaster GMT? Thanks so much in advance. I am sorry I can't help you on the accuracy issue coz I wear my Rolex primarily for show.....when I need up to nanosecond accuracy, I have a little Casio Baby-G tucked in my jeans coin pocket.

To clarify, it's an Omega Seamaster (not Speedmaster) GMT. Black dial. I don't have any pictures loaded up on Photobucket at this point of time, will post here when I get that done.

[whw]

Originally Posted by Art161

It might be that I am not understanding something here. You say you set the time on the watch and then wore it all day, and conclude that it must be fully wound at that point. Did you wind the watch for 40-45 360 degree turns of the winding crown when you set the time? When you wear the watch and provide "normal" movement of your wrist, you are just about maintaining the power reserve at the level it was when you starting wearing it.

Let's look at it this way. Say the watch has stopped. You can't just start wearing it and expect it to build up much of a power reserve, if any reserve at all. If it is at half the reserve when you start wearing it, it will probably be at approximately half reserve when you take it off.

Wearing the watch with "normal" movement of your wrist simply maintains the power reserve at approximately what it was when you put it on.

I hope this helps.

Art161, are you certain that normal wear will not build up the power reserve? If find that hard to comprehend. Eg. if my watch has say eg. half power reserve, and I wear it from eg. 7am to 11pm that day, you are saying that my power reserve will still be half at 11pm. My understanding is that it normally takes about 6 hours of normal active wear (ie. not sitting down watching a movie) to take the power reserve to full.

I don't have any watch with a power reserve indicator, so I have not been able to test this out. I am sure some other forumers with power reserve watches can fill us in here.

When I set my watches, I normally turn the crown 30-40 times to wind it up first. But in my case above, the watch already had power in it (but I don't know exactly how much) as it I took it off a watch winder. It was on the watch winder for around 7 days (I presume it was at full power reserve when I placed the watch on the watch winder).

Anyway, it's a shame that, after reading the post above by ayecarumba, that so many of his collector friends find that their Rolex keeps the worst time (compared to others).

I still LOVE my GMT IIc! But this accuracy thing BUGS me. Lol.

[C. Davidson]

Originally Posted by Art161

Did you wind the watch for 40-45 360 degree turns of the winding crown when you set the time? When you wear the watch and provide "normal" movement of your wrist, you are just about maintaining the power reserve at the level it was when you starting wearing it.

Originally Posted by Z-Sub

If it is still slow and unsteady, you should bring it back for another service and have them adjust it so it is a bit faster than slower. it's simple adjustment by Rolex. It would bother me very much as well.

Sorry to hear that you are having problems with your GMT. Both Z-Sub and Art gave great suggestions.

How people wear their watches during the day various quite drastically from person to person. A computer programmers daily routine versus say a police officers will have two different effects on the watch. The computer programmers Rolex will run on "low" power and Im sure that the police officers Rolex will run on "full" power. The main difference being the cop moving his arm around more than the programmers wrist that stayed in the same basic position all day long. Art's question on power reserve is a good one. If you set down your watch at night with "low" power, your rate will vary beyond COSC standards. Definitely try his suggestion out prior to sending the watch back to Rolex.

Communicate your daily wearing habits with the Rolex Service Center in your area. This should help them a great deal in assisting you.

The 3186 movement is still fairly new (even though its based on the 3185) and perhaps there are still a few kinks that Rolex may be smoothing out. If there is something amiss in your Rolex, taking it to the service center helps Rolex to further perfect their product, which helps everyone out in the long run.

[Art161]

Originally Posted by whw

Art161, are you certain that normal wear will not build up the power reserve? If find that hard to comprehend. Eg. if my watch has say eg. half power reserve, and I wear it from eg. 7am to 11pm that day, you are saying that my power reserve will still be half at 11pm. My understanding is that it normally takes about 6 hours of normal active wear (ie. not sitting down watching a movie) to take the power reserve to full.

I don't have any watch with a power reserve indicator, so I have not been able to test this out. I am sure some other forumers with power reserve watches can fill us in here.

When I set my watches, I normally turn the crown 30-40 times to wind it up first. But in my case above, the watch already had power in it (but I don't know exactly how much) as it I took it off a watch winder. It was on the watch winder for around 7 days (I presume it was at full power reserve when I placed the watch on the watch winder).

Anyway, it's a shame that, after reading the post above by ayecarumba, that so many of his collector friends find that their Rolex keeps the worst time (compared to others).

I still LOVE my GMT IIc! But this accuracy thing BUGS me. Lol.

No, not completely sure. I wear my watch 24/7, and I don't have reserve power issues. It is just second hand (no pun intended) information. Whether wearing the watch maintains the same reserve power, whether reserve power decreases, or whether reserve power increases is quite dependent, I am relatively sure, on how vigorously you move your wrist while wearing the watch. I would say it is not a good idea to start off with a watch that is getting low in reserve power and just put it on your wrist before winding the watch fully. My understanding is that a full wind is 40-45 360 degree turns of the winding crown. You can't over wind the watch, so go for it!

I think a valid question is, "What is active wear?" I'm not really that active overall. I sit at the computer or watch TV quite a bit. So what I consider "normal" activity may be considered less than "normal" by others. I usually take an hour's walk every day, but that doesn't always happen. Yesterday I was watching a lot of football on TV, and didn't take my walk.

If you wear your watch from 7 AM to 11 PM, and have it set aside from 11 PM to 7 AM and it never stops, then that would tend to support the position that it must be increasing the power reserve when you wear it. I have read, however, that before the watch actually stops, the timing becomes erratic, and the watch could actually gain time. I'm not saying that the lack of accuracy of your watch is because of being towards the end of the power reserve, but this action of the watch is something to keep in mind.

One test you could do is manually give the watch a full wind, set it aside and see how long it takes to run down. Then manually give the watch a full wind and wear it normally for a week or so. Then set it aside and see how long it takes to run down. Then manually give the watch a full wind, set it aside for half the length of time it took to run down when wound manually and set aside without wearing, and then wear it normally for a week or so. Then set it aside and see how long it takes to run down. This should give you an indication as to how your particular watch maintains power reserve for your use of the watch.

If you do the above test, please post your results.

[C. Davidson]

Originally Posted by whw

When I set my watches, I normally turn the crown 30-40 times to wind it up first. But in my case above, the watch already had power in it (but I don't know exactly how much) as it I took it off a watch winder. It was on the watch winder for around 7 days (I presume it was at full power reserve when I placed the watch on the watch winder).

After reading your posts a second time, I caught this nugget. I had a problem with some of my mechanical watches (various Swiss brands) not being fully powered by my watch winder. Their rates were inconsistant and some even stopped! The problem was that they were not recieving enough power from the watch winder. It is possible that your GMT was slowly powering down on the winder, even if it was running for 8 hours a day.

A fair comparison of daily rates would be the following for 7 days:
Fully wind watch 50 times on day one. Sychronise with Atomic Clock. Wear watch for 7 days. Everyday at the same time, compare time with Atomic Clock time. Go from there.

Power might not be the problem, but trying this out may save you another trip to a Service Center.

[golfball123]

i hv yet to check the accuracy by the seconds on my gmt....or rather all my auto watches.

[Singslinger]

Sorry to hear about your GMT's timing being off. I don't own one myself but I have a colleague at work who bought one when it was first issued a year ago and he swears that it's the most accurate watch he has - and he owns a couple of Langes, Pateks and Rolexes. Could be that your piece is an odd one out?

[Erix]

Hi all.

I could not stand it if my watch was slow, a couple of seconds fast is ok but slow no way.
It is an easy fix to regulate the watch, at some places they even do it while you are waiting.

BUT it is important that you leave some kind of information about how slow the watch is.
Because you watch migth run dead-on in the machine they have when they check the accuracy, but since it is a mechanical watch your wearing habits will probably cause a difference from the machine measure.

[whw]

Thanks for all the suggestions guys. I am planning to give the watch a good 40-45 full 360 degree winds tomorrow morning, then resynchronise it, then wear it for the full day (except for sleep time) and monitor the accuracy on a daily basis. Will keep you all updated!

[Ivy League]

Just another observation from a new GMT IIc owner......I've had mine for 4 weeks now.
I sync my watch to time.gov as well and it seems to be consistently fast by 2+ to 3+ seconds per day. Still within COSC specs so no problems there.
However, I do notice that the minute hand is never 100% aligned to the minute markers on the dial when the second hand completes the 12:00 cycle.
How do you guys manage this ?

[Noonan]

Originally Posted by whw

Art161, are you certain that normal wear will not build up the power reserve? If find that hard to comprehend. Eg. if my watch has say eg. half power reserve, and I wear it from eg. 7am to 11pm that day, you are saying that my power reserve will still be half at 11pm. My understanding is that it normally takes about 6 hours of normal active wear (ie. not sitting down watching a movie) to take the power reserve to full.

One of my watches has an indicator for the power reserve and wearing it will not wind it to full. If it's at half power when I put it on, it'll be just a bit more wound than that by the end of the day. It increases but only slightly. But I sit at a desk all day so it's not winding itself as much as it would if I were more active.

[Tools]

I don't think that I would get wrapped up in how much power reserve your watch has as it relates to it's time-keeping... Unless you are on the ragged edge of either extreme, the watch should perform consistently..

Also you can't really tell much by taking "timing" checks throughout the day....a watch will swing considerably depending on what your activity is throughout the day because of movement, temperature, pressure, gravity etc..

The only way to know your wearing habits, and the effect on timing, is to set it once, wear it normally for a week, and then check it again, dividing by the number of days..

With this known daily average deviation, you can take the information to your watchmaker and say....My watch consistently runs 3 seconds slow per day......please time it 3 seconds per day faster than what your machine says it runs...

As far as what friends, collectors, "experts", etc. say about Rolex being less accurate than other brands....Poppycock....

Everybody who is well respected in the horologic community knows for a fact that Rolex makes some of the best functioning and consistent movements on the planet.... It's what they have made their reputation on.

[mpkRolex]

Originally Posted by whw

Bought my first ever Rolex, a beautiful SS GMT IIc in May this year. Wrote about it here: http://www.rolexforums.com/showthread.php?t=46876

After about 4 months of use, the watch was consistently about 4.5-5 seconds slow per day. So I took it to the Rolex Service Centre to get it regulated. After that it was about 1.5 seconds slow per day, which is alright with me. But would have preferred it to be faster instead of slower. I don't mind if the watch is slightly fast, but it gets to me if its slower.

2 days ago the watch was behind by about 45 seconds, so I resynchronised the watch with time.nist.gov. At the end of the day the watch was slow by 1.5 seconds. Which is alright. Note that I wore the watch for the whole day after resynchronising it earlier in the morning. So the watch is surely fully wound up at that stage. At the end of the day I took it off to sleep. The next morning (ie this morning), the watch is slow by 5 whole seconds (ie. it lost another 3.5 seconds during the night (about 10 hour period).

I notice (in the past) that the watch stays consistent if I wear it for the whole day, but not wearing it (or even putting it on a winder) will cause the watch to slow down by more that the usual rate. So the power reserve somehow is not able to keep the watch running consistently even for a 24 hour period of inactivity.

I notice that if I wear it the whole day, before I take off my watch to sleep, it picks up a 1-2 seconds. So the net variance is about 1.5 seconds per day.

Now, don't get me wrong. I love this watch tremendously. And a few seconds off per day is really nothing and acceptable under COSC. BUT when I compare it to my Omega Seamaster GMT (that uses an ETA-2892), the Omega trumps the Rolex in terms of accuracy. My Omega is consistently fast 3 seconds per day. I can leave the watch inactive for 40 hours and it still maintains the +3 seconds accuracy. And the end of a whole day of use it is not faster or slower that what it should be. It is by far the most consistent watch is my small collection.

Any comments or feedback?

I dont have a GMTIIc, but my Omega Speedy is more accurate than my Submariner. And my Wenger quartz is the most accurate machine among the three

[rilu]

good luck on your testing. some watch winders work good some don't, rolex once told me to make sure the winder does at least like 800? revolutions per day, and that it is set to wind in both directions and make sure it was at the proper incline for the wight to rotate properly, some winders don't come with directions to tell you which way the box should lay and how the watch properly sits in or what settings to put them on. this was a long time ago they said this so i would call rolex and ask them to tell you what they recommend. watches need diferent settings, like the 7750 only winds in one direction so if you put that on the winder and it turns the wrong way it will never wind up the watch.
to make the story short my friend was putting his watch in the winder with the dial facing up twards the ceiling and when it rotated it never wound the watch because as it rotated the weight didn't move, not winding the watch, once he put the winder on side and the face of the watch pointed to the wall gravity took over and his watch is working perfectly. he is retired"watches tv all day " so watch never wound on his wrist, but the 8 ours on the winder at night maintains it always at a good wing.

[BigHat]

Virtuallly all Rolex watches wind both ways and 650 turns is right.

From the Orbita Database:

ROLEX Most Rolex Automatics Most Rolex Movements Both 650

[f16570]

Interesting, I will not bore you with how accurate my Exp II is after I had it regulated.
Keep us posted as to how you get on.

[Erix]

Originally Posted by Ivy League

However, I do notice that the minute hand is never 100% aligned to the minute markers on the dial when the second hand completes the 12:00 cycle.
How do you guys manage this ?

Stop the seconds hand at 12:00, move the minute hand to the minute marker and let go....

[Dan Pierce]

My K series [2002] GMT II is consistantly -2 sec slow per day. Doesn't bother me a bit that it runs slow vs fast. Most important is the consistancy. Plus, I set it one minute ahead of the correct time and know that my watch is within a minute of the atomic clock for 2 months.! Not bad at all.
dP

[Ivy League]

Thanks Erix:

Just tried your suggestion and I'll keep an eye on it.

[Erix]

Originally Posted by Ivy League

Thanks Erix:

Just tried your suggestion and I'll keep an eye on it.

U R welcome.

[ayecarumba]

Well I certainly will admit that my checks were not done in a COSC lab, but by setting the watch/hacking with the online atomic clocks at NIST or the USNO....after 24 hours I checked them and my own results were:

Rolex GMT IIc: -7 secs
Breitling Cosmonaute: -3 secs
Omega Speedmaster Pro: +3 secs



that was after a single day..my GMT seems to run consistently about -7 secs/day...If someone will donate a lab coat and a case of beer, I'll be happy to carry out some more thorough checks!

[haakon59]

Timing checks after a few hours generally give you a limited feel for how accurately a watch will perform over longer time--try a week or so instead and then measure the accuracy. Automatic watches will naturally vary a bit depending on wearing habits (how much the watch is wound) and things like temperature, etc. If you want to the second consistency, you are much better off with quartz. Personally, I like automatics and have learned to tolerate their idiosyncrasies.

[Perdu]

Well the answer to this problem is to wear your watch 24x7 and it will keep excellent time. I also have the Omega GMT and have a similar situation with that. If I leave the watch for 20+ hours it will slow down, but if I wear it, it will consistently keep time to minus one second a day. Since I wear my watch all the time it really isn't a factor. I'm not sure what a watchmaker has to adjust to make a watch run at the same rate as it unwinds for 40 hours? Anyone?

For time setting I do the same as Dan. Add one minute and adjust every 60 days.

[SLS]

Originally Posted by whw

....So the power reserve somehow is not able to keep the watch running consistently even for a 24 hour period of inactivity....

This is true with any automatic watch. A fully wound mainspring will actually cause the watch to run slower and conversely you watch will actually speed up when the power reserve is low. So measuring the accuracy of your watch over a 24 hour period for a week will give you a better gauge of how your watch is performing. I used to get caught up in how accurate my watch was, but I found it more fun to just enjoy them....what's a few seconds a day in the whole scheme of things, enjoy the GMT!
~Scott