Accuracy Thoughts

[Coopdog]

Sometimes it just strikes me how amazing these little machines are. My GMT Master II that I’ve had for about 6 months hasn’t had an “official” accuracy test until this week. It’s running ~-0.5s/d (lost 2 seconds over 4 days).

That’s incredible. We take it for granted since time isn’t hard to calculate digitally now, but that’s a physical machine that I don’t really maintain at all running at 99.999421% accuracy. While it heats up and cools down on my wrist, gets bounced around while I walk, has the mainspring wind down overnight and get back to full torque during the day, etc. Pretty crazy.


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[tgoose1]

That's excellent and when a current Rolex movement is regulated that close to +-(0)/day, positioned overnight face-up or face-down will tend to gain a little, and crown-up or crown-down will slow the movement a bit if needed. This has been discussed over the years, Rolex included this tip with the new watch owner's manual/paperwork in the past.

[padi56]

Today most all modern day movements most brands when regulated correctly can run too, or inside the COSC spec. But agree for any mechanical movement to run within a few seconds either way out of 86400 in a day is a mechanical marvel.

[Pentameter]

I don’t take accuracy for granted at all - I marvel at their ability to get high accuracy with these mechanical movements, which by their nature are prone to irregularities. Honestly that’s one of the biggest selling points of a Rolex that I have come to realize after owning one for a while - they are both highly accurate and tank-like durable, which gives you a huge feeling of comfort knowing that your watch is always going to be accurate, you don’t have to worry about damaging it, and lastly it’s money on your wrist in an emergency. I have never felt that level of assuredness with a watch before, and like I said to me that’s one of the biggest benefits of these watches IMO. It’s hard to put into words, but it’s real.

[Coopdog]

Originally Posted by tgoose1

That's excellent and when a current Rolex movement is regulated that close to +-(0)/day, positioned overnight face-up or face-down will tend to gain a little, and crown-up or crown-down will slow the movement a bit if needed. This has been discussed over the years, Rolex included this tip with the new watch owner's manual/paperwork in the past.

Yes, and amazingly in my case it is 0.5s/day slow with the crown up every night tested. I haven’t tried changing the position in this current test, but I’m guessing it’s just about dead on 0/d if I adjusted how it was positioned at night. And this test does include me wearing the watch all day for 4 days in a row. Really remarkable.


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[Mystro]

I am a automatic watch accuracy freak. I love to see just how capable a mechanical watch can get. It’s one of the few unbiased ways to separate the marketing hype from real tangible results. Longer Power reserves coupled with a accurate/stable movement is what really separates the real super stars from the jewelry.

[Coopdog]

Originally Posted by Pentameter

I don’t take accuracy for granted at all - I marvel at their ability to get high accuracy with these mechanical movements, which by their nature are prone to irregularities. Honestly that’s one of the biggest selling points of a Rolex that I have come to realize after owning one for a while - they are both highly accurate and tank-like durable, which gives you a huge feeling of comfort knowing that your watch is always going to be accurate, you don’t have to worry about damaging it, and lastly it’s money on your wrist in an emergency. I have never felt that level of assuredness with a watch before, and like I said to me that’s one of the biggest benefits of these watches IMO. It’s hard to put into words, but it’s real.

Totally agree. It’s not necessarily hard to regulate a well made mechanical movement these days, but the consistency that a Rolex comes just out of the box with no fuss, no thought - it’s reassuring. And in my experience they stay true through years of use which is even more remarkable.


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[Rolexoman]

My DJII is the one watch I have that’s the farthest out on Rolexes current accuracy standard with a daily gain of +4 secs and I’m ok with that, my Tudor BB runs at +.5 secs a day and lastly my Omega runs at -1.5 SPD

I know a lot of you accuracy guys cringe at my numbers since lots of you are getting close to zero gain or loss

[Chiboy]

I keep track of my Daytona, not because I'm going to complain about it or send it in if it's off a second or two a day, but because I marvel at how accurate it is. It stopped after almost two months of wearing but not winding and was about six seconds slow in total. I wound and set it and now it's a second fast after more than three weeks.

I know how many seconds there are in a day, but I derive a bit of pleasure out of how amazingly accurate my watch is on my wrist in my climate with my wear patterns.

[chicagowatchman]

my day date masterpiece lost 16 seconds over 3 months remarkable!

[othertbone]

Originally Posted by Coopdog

Sometimes it just strikes me how amazing these little machines are. My GMT Master II that I’ve had for about 6 months hasn’t had an “official” accuracy test until this week. It’s running ~-0.5s/d (lost 2 seconds over 4 days).

That’s incredible. We take it for granted since time isn’t hard to calculate digitally now, but that’s a physical machine that I don’t really maintain at all running at 99.999421% accuracy. While it heats up and cools down on my wrist, gets bounced around while I walk, has the mainspring wind down overnight and get back to full torque during the day, etc. Pretty crazy.


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Waiting for some GS spring drive lover to comment lol

[watchmaker]

Originally Posted by Coopdog

Totally agree. It’s not necessarily hard to regulate a well made mechanical movement these days, but the consistency that a Rolex comes just out of the box with no fuss, no thought - it’s reassuring. And in my experience they stay true through years of use which is even more remarkable.


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It's only easy when the person that assembled/worked on it before you left it in a good condition (or the watch hasn't suffered hard impact damage).

Regulating a watch can often require far more than turning timing screws. The balance must be poised as accurately as possible and then the hairspring flatness and centring must be achieved by manual manipulation of the spring.

Only then would you look at the timing screws/nuts/eccentrics/curb pins - which is often mistaken for all that is involved in regulation.

[Coopdog]

Originally Posted by watchmaker

It's only easy when the person that assembled/worked on it before you left it in a good condition (or the watch hasn't suffered hard impact damage).



Regulating a watch can often require far more than turning timing screws. The balance must be poised as accurately as possible and then the hairspring flatness and centring must be achieved by manual manipulation of the spring.



Only then would you look at the timing screws/nuts/eccentrics/curb pins - which is often mistaken for all that is involved in regulation.

I don’t mean it doesn’t take skill, I mean it is highly replicable. And I would bet Rolex does not poise their balance wheels manually at this point. They probably have machines that can sense tiny errors in rotating mass and then adjust the screws as required without much human intervention. I would guess they also have optics that can assist with balance spring position.




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[Old Expat Beast]

I have a couple of very basic half-century-old Seikos running -/+ 0 secs/day.

https://www.rolexforums.com/showthread.php?t=694443

[Coopdog]

Originally Posted by othertbone

Waiting for some GS spring drive lover to comment lol

I actually love the spring drive movement and have owned one in the past. I think the spring drive is an achievement that isn’t appreciated by many people because most people don’t really understand it. But for practical purposes my Rolex is as accurate as a spring drive. I’d have to wear my Rolex for over a month straight for it to be off by half a minute - and I rotate my watches so they never run that long continuously.


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[Coopdog]

Originally Posted by Old Expat Beast

I have a couple of very basic half-century-old Seikos running -/+ 0 secs/day.

https://www.rolexforums.com/showthread.php?t=694443

That’s great. Do they perform to that level when you wear them? I’d think they would be more prone to temperature and vibration affecting the rate but I have little experience with older mechanical movements.


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[Old Expat Beast]

Originally Posted by Coopdog

That’s great. Do they perform to that level when you wear them? I’d think they would be more prone to temperature and vibration affecting the rate but I have little experience with older mechanical movements.


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Yes, sure, on the wrist there is a couple of secs change during the day, but being older movements they are also more sensitve to overnight positioning than modern Rolex movements so can be kept dead-on pretty much indefinitely if desired.

[JoseR]

I've always found it amazing how a mechanical watch keeps accurate time with all those small parts on the movement. My AK which I got in April keeps very accurate time. My mom asked me why I paid so much for a watch. I tried to explain it to her but got the whatever look. IMO, a real watch is mechanical....not quartz. Only own two quartz and they were gifted to me. Never again would I want a quartz watch...

[Catatafish]

My explorer is running + .4 a day worn and I couldn't be happier. Accuracy is very important to me and Rolex didn't let me down. It justifies the price to me that they have engineered and regulated to such high standards.

[s7horton]

Originally Posted by Catatafish

My explorer is running + .4 a day worn and I couldn't be happier. Accuracy is very important to me and Rolex didn't let me down. It justifies the price to me that they have engineered and regulated to such high standards.

Agreed. My smurf was adjusted by my AD and now runs +0.3 secs per day. Perfect IMO.


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[BlueHeron]

New DJ41 at +-0 after four days....spiritual

[Muxi]

Try to find an off-the-wrist position that would compensate for that tiny deviation and you’re all set!

[Anamelistic]

I have a Tudor 79230 that's under -0.30/spd. If it comes back anything worse than that I usually just drop it off a chest high dresser and it fixes itself. Then I have a 114060 that I just bought (2nd hand) and its almost outside of Rolex -2 spd

[bruinmd]

So far-- and yes I know it's a limited sample size-- I'm finding the 3235 in my BLRO to be more accurate than the 3135 in my LVC. It's astounding how accurate the BLRO has been thus far.

[Oxfordian]

I've never really monitored closely any of my watches to see exactly how accurate they are, I tend to set the watch on a Sunday morning against my reference time then reset the watch the following Sunday.

What astounds me is that the watches, two automatics from Rolex and Omega and a manual wind Speedmaster are never too far off my reference time at the end of their rotation, for something that is powered by springs, cogs, levers and wheels, which goes through so much during the course of the day yet maintains such accuracy is incredibly impressive.