Is a COSC Tested Movement The Best In The Watch World

[padi56]

With so many today on forum with accuracy OCD its most important to remember that a "COSC certified chronometer" is not the Holy Grail of watchmaking. With the high quality of modern day robotised manufacturing, this test is not that important in reality. As today most decent modern watches from all countries even some from China like the Seagull movements, when adequately adjusted, should be able to match the performance specified by the now quite antiquated Swiss COSC test even the newer Rolex introduced -2+2 spec.

A chronometer certificate is not a guarantee of future accuracy for life only a certification that the bare uncased movement was tested at the COSC and passed at time of testing same for the new Rolex machine -2+2 test. Watch movements that have been certified can get out of adjustment and still perform quite poorly outside the COSC spec or the -2+2 spec. Movements that are not certified could still exceed the COSC standards with just simple regulation.Many of todays manufacturers may have simply chosen to bypass the expense of the certification process its quite expensive to test every single movement. But today IMHO the COSC is little more than a pure marketing tool and means little in actual performance only the fact its been tested at that time.Now when the thousands of movements that get tested and then shipped back to the manufactures those that have passed plus the ones that fail yes some do fail even ones from Rolex.The failed movements are perhaps re-oiled re tested on a machine then shipped back to the COSC to test again.Now a lot could happen to any movement on its way from being certified shipped back then stored then finally cased.In the case of Rolex they must have many thousands in store waiting to be cased then shipped around the world to the various ADs

The term "Superlative Chronometer" is a now trademark of Rolex. The addition of the word "Superlative" in front of the official designation of Chronometer is merely a Rolex marketing angle to give a more distinguished sound to the chronometer status of their products . As all watches that have earned the privilege of bearing the official Swiss designation of "Chronometer" have to meet the exact same COSC standards. Any words added before or after the official designation of "Chronometer" are merely more marketing which Rolex is very good at.There are not any different grades or levels of chronometer certification,for movements of Rolex size but Rolex would like you to think there are.


When thinking of accuracy its very important to remember that even when a mechanical watch is allowed to vary by COSC standards +6/-4 seconds per day, that does not mean it will consistently vary by that high or low amount each day. Mechanical movements that self regulate say by resting in different positions over night its very rare for this to happen.All Mechanical watches are noticeably affected by the gravitational pull of the Earth. It only takes a performance distortion of 1/1000th of a percent for a mechanical watch movement to be one second less accurate in a day. So to get any mechanical watch to self regulate with zero tolerance is IMHO something that's very very rare maybe one it quite a few thousand or even million

Likewise, "Certified Chronometer" also means nothing different than just "Chronometer." It is a redundant phrase--since Chronometer status is the certification the certified is just more pure marketing, and you know what they say about marketing well it often baffles brains.

[SMDRFE]

I think COSC is good for guaranteeing a certain reasonable for modern times level of accuracy in mechanical watch movements, but yes Rolex has shown that one can do even better than that.

I have a Seiko Pepsi Turtle (SRPE99) that I got for fun as a freebie. Really nice watch, and has the Seiko 4R36 movement. Runs within COSC most of the time, but can drift outside of it a bit. My son (14) has a Seiko SRPD93. Same exact movement but runs about -20 to -30 spd. No one really wants to touch them for adjustments either, as they're so touchy to adjust and can just as easily send them way off course.

I think COSC is more a reflection of the watchmakers attention to detail, willingness to go the extra mile, and to spend the extra money to guarantee that level of accuracy. Even then it's still not really a gaurantee as the movements are measured prior to casing. Both of my Breitlings with B01 movement generally ran +6-8 spd for the first year outside of spec, but eventually settled down into the +2-4 spd range. One managed to get magnetized somehow, so runs a bit erratic and the reserve isn't nearly 70 hours, but still generally within COSC!

[padi56]

Well even the Chinese made Seagull ST 19 mechanical movement after regulation can run well inside COSC even this new -2+2 pec cost of movement under $100.

[csaltphoto]

Originally Posted by padi56

Well even the Chinese made Seagull ST 19 mechanical movement after regulation can run well inside COSC even this new -2+2 pec cost of movement under $100.

Can it do that for years at a time without additional regulation? That seems to be one of the strengths of Rolex movements is being able to run for years or decades while staying in spec.

[Old Expat Beast]

Originally Posted by csaltphoto

Can it do that for years at a time without additional regulation? That seems to be one of the strengths of Rolex movements is being able to run for years or decades while staying in spec.

I've got two uncertified, unserviced Tudor ETA movements (BB and Heritage Ranger) recently showing -/+ 0 secs/day with 300+ beat error and negligible or no beat error after about a decade of fairly regular wear. I'm not sure I'd put money on two new 32xx movements showing those numbers after ten years.

[Dirt]

Originally Posted by Old Expat Beast

I've got two uncertified, unserviced Tudor ETA movements (BB and Heritage Ranger) recently showing -/+ 0 secs/day with 300+ beat error and negligible or no beat error after about a decade of fairly regular wear. I'm not sure I'd put money on two new 32xx movements showing those numbers after ten years.

Agreed.

I think I could find better ways to throw my money out the window. Unless the odds were compelling and I was drunk enough.

[Easy E]

Originally Posted by Old Expat Beast

I've got two uncertified, unserviced Tudor ETA movements (BB and Heritage Ranger) recently showing -/+ 0 secs/day with 300+ beat error and negligible or no beat error after about a decade of fairly regular wear. I'm not sure I'd put money on two new 32xx movements showing those numbers after ten years.

Or 10 months

[Dirt]

Originally Posted by Easy E

Or 10 months

You're terrible.
I hope that pile on that we won't discuss doesn't flow on from comments like that.
So many awful people around here that are Non-believers and Backsliders.

[Dirt]

Originally Posted by csaltphoto

Can it do that for years at a time without additional regulation? That seems to be one of the strengths of Rolex movements is being able to run for years or decades while staying in spec.

Now iirc, Peter may have admitted that it had to be chased a bit to get that sort of performance, but wouldn't necessarily be drawn on whether it was going to be stable.
At least stable in terms of Rolex Chronometer grade movements in general that have a Free Sprung Balance, when pressed on it back in the day when he first put it out there

[padi56]

Originally Posted by csaltphoto

Can it do that for years at a time without additional regulation? That seems to be one of the strengths of Rolex movements is being able to run for years or decades while staying in spec.

Possible as today most Rolex watches get a very pampered life with these machine winder things and the rest of today's Rolex toys.But most all watches movements today could need regulation, but more important good regular service to prolong they life.

[wilsonpepper]

Originally Posted by padi56

Well even the Chinese made Seagull ST 19 mechanical movement after regulation can run well inside COSC even this new -2+2 pec cost of movement under $100.

I agree with that !

Also the Dandong factory in Shanghai puts out some pretty good movements. Although some may need to be "serviced" right out of the factory, their accuracy is impressive.

[padi56]

Originally Posted by wilsonpepper

I agree with that !

Also the Dandong factory in Shanghai puts out some pretty good movements. Although some may need to be "serviced" right out of the factory, their accuracy is impressive.

Agree I bought a Alpha watch I was going to use the movement in another old chronograph watch.This movement was based on the old Swiss Venus 75 a fine movement. Seagull bought the tooling rights when they went bust back late 1960 early 1970s.They did modify it a bit with higher beat rate and power reserve and was quite surprised when tested on my watchmaker friend machine it was showing +7 daily average.But after regulations got to way in COSC spec and it was consistent not bad for a $60 movement cost at that time.My grandson is still wearing the watch and now almost ten years old,I have serviced and re-regulated it a few time but still ticking.

[TikTok]

Some may find these interesting…

https://www.ablogtowatch.com/accurac...nical-watches/

https://www.ablogtowatch.com/accurac...nical-watches/

[TikTok]

Originally Posted by TikTok

Some may find these interesting…

https://www.ablogtowatch.com/accurac...nical-watches/

Posted the wrong link first time around

https://watchgauge.com/blogs/educati...anical-watches

[KatGirl]

Originally Posted by padi56

With so many today on forum with accuracy OCD its most important to remember that a "COSC certified chronometer" is not the Holy Grail of watchmaking. With the high quality of modern day robotised manufacturing, this test is not that important in reality. As today most decent modern watches from all countries even some from China like the Seagull movements, when adequately adjusted, should be able to match the performance specified by the now quite antiquated Swiss COSC test even the newer Rolex introduced -2+2 spec.

A chronometer certificate is not a guarantee of future accuracy for life only a certification that the bare uncased movement was tested at the COSC and passed at time of testing same for the new Rolex machine -2+2 test. Watch movements that have been certified can get out of adjustment and still perform quite poorly outside the COSC spec or the -2+2 spec. Movements that are not certified could still exceed the COSC standards with just simple regulation.Many of todays manufacturers may have simply chosen to bypass the expense of the certification process its quite expensive to test every single movement. But today IMHO the COSC is little more than a pure marketing tool and means little in actual performance only the fact its been tested at that time.Now when the thousands of movements that get tested and then shipped back to the manufactures those that have passed plus the ones that fail yes some do fail even ones from Rolex.The failed movements are perhaps re-oiled re tested on a machine then shipped back to the COSC to test again.Now a lot could happen to any movement on its way from being certified shipped back then stored then finally cased.In the case of Rolex they must have many thousands in store waiting to be cased then shipped around the world to the various ADs

The term "Superlative Chronometer" is a now trademark of Rolex. The addition of the word "Superlative" in front of the official designation of Chronometer is merely a Rolex marketing angle to give a more distinguished sound to the chronometer status of their products . As all watches that have earned the privilege of bearing the official Swiss designation of "Chronometer" have to meet the exact same COSC standards. Any words added before or after the official designation of "Chronometer" are merely more marketing which Rolex is very good at.There are not any different grades or levels of chronometer certification,for movements of Rolex size but Rolex would like you to think there are.


When thinking of accuracy its very important to remember that even when a mechanical watch is allowed to vary by COSC standards +6/-4 seconds per day, that does not mean it will consistently vary by that high or low amount each day. Mechanical movements that self regulate say by resting in different positions over night its very rare for this to happen.All Mechanical watches are noticeably affected by the gravitational pull of the Earth. It only takes a performance distortion of 1/1000th of a percent for a mechanical watch movement to be one second less accurate in a day. So to get any mechanical watch to self regulate with zero tolerance is IMHO something that's very very rare maybe one it quite a few thousand or even million

Likewise, "Certified Chronometer" also means nothing different than just "Chronometer." It is a redundant phrase--since Chronometer status is the certification the certified is just more pure marketing, and you know what they say about marketing well it often baffles brains.

That last paragraph is misleading, as the C.O.S.C. DOES CERTIFY EACH MOVEMENT, THAT IT TESTS, AS A CHRONOMETER.

KAT


Sent from my iPad using Tapatalk

[Dirt]

Originally Posted by KatGirl

That last paragraph is misleading, as the C.O.S.C. DOES CERTIFY EACH MOVEMENT, THAT IT TESTS, AS A CHRONOMETER.

KAT


Sent from my iPad using Tapatalk

Either way Kat.
It's all about the marketing.
Real Chronometers aren't worn on a wrist, and in some ways it's a redundant certification for marketing. Especially since the Japanese blew it apart.
But it's little more than increasingly becoming a stepping stone for Omega, Rolex and others rather than an outright cornerstone since Metas and the Rolex "Officially Certified"(since mid 2015) standard effectively builds upon the Chronometer tag.

[Phrank]

Fascinating as always, from the latest Rolex Magazine Issue #11:

The article, "Geography of Excellence":

From COSC certification of -4/+6 from which the watch, "then heads for Superlative Control, located in the underground floors of the Acacias site."

The Superlative Chronometer on Rolex watches, "the criteria are strict. The rate of deviation must not exceed -2/+2 seconds per day, a much tighter requirement than that of the COSC chronometer certification standards."

[KatGirl]

Originally Posted by Phrank

Fascinating as always, from the latest Rolex Magazine Issue #11:

The article, "Geography of Excellence":

From COSC certification of -4/+6 from which the watch, "then heads for Superlative Control, located in the underground floors of the Acacias site."

The Superlative Chronometer on Rolex watches, "the criteria are strict. The rate of deviation must not exceed -2/+2 seconds per day, a much tighter requirement than that of the COSC chronometer certification standards."

The fact that Rolex has stricter standards than C.O.S.C. Is the marketing ploy, and rather brilliant.

Kat


Sent from my iPhone using Tapatalk

[padi56]

Originally Posted by KatGirl

The fact that Rolex has stricter standards than C.O.S.C. Is the marketing ploy, and rather brilliant.

Kat


Sent from my iPhone using Tapatalk

The bare uncased movements are still tested at the Swiss COSC to a AVERAGE -4+6 seconds to bare the name chronometer on the dial.Rolex further tests with movement in its case to a precision -2+2 seconds time of testing on machine in controlled environment.

[Sauzo]

I think Metas is better than Cosc. Sure Cosc is +2/-2 and Metas is +0-5 but I would rather have my watch run fast than slow. Never hurts to show up early to anything but being late can be bad.

[Dirt]

Originally Posted by Sauzo

I think Metas is better than Cosc. Sure Cosc is +2/-2 and Metas is +0-5 but I would rather have my watch run fast than slow. Never hurts to show up early to anything but being late can be bad.

In the Omega context.
I thought they went COSC on the movement(as they do) before Metas.
With numbers so impressive either way.
Is there any real difference in real practical terms on the wrist between them?

[padi56]

Originally Posted by Sauzo

I think Metas is better than Cosc. Sure Cosc is +2/-2 and Metas is +0-5 but I would rather have my watch run fast than slow. Never hurts to show up early to anything but being late can be bad.

I am sure if any watch was say running 10 seconds slow a day it would not effect timing for any appointments or catching trains, buses, ships,or plane's.Even after a say a week or wearing watch would be just over 1 minute slow.If anyone's life today is run to the exact second then I feel very sorry for them to have such a hectic life.

[CarlOver]

Originally Posted by padi56

I am sure if any watch was say running 10 seconds slow a day it would not effect timing for any appointments or catching trains, buses, ships,or plane's.Even after a say a week or wearing watch would be just over 1 minute slow.If anyone's life today is run to the exact second then I feel very sorry for them to have such a hectic life.

Good point Peter. Same with your car…no big deal if it’s getting significantly less miles per gallon than quoted. Or significantly less HP. What if you got 5.4% instead of 5.5% on a CD. Who would miss that? It wouldn’t change anything really.

I think you get my point.

[Driver8]

Good post, except for the fact that while the "Superlative" part of "Superlative Chronometer" used to be no more than simple marketing spin, it is now the name for Rolex's +/-2 sec in-house testing/certification which is a combination of COSC followed by Rolex's own testing. Much the same as Omega's "Master Chronometer" which is a combination or COSC, followed by METAS.

But yes, it's eminently possible to regulate most movements to COSC, or near COSC, standards. For example, I have a number micro-brands running Seiko NH35/NH34's (which are £40 movements) that are all within COSC, and one that gains less than a second a week to the atomic clock.

[EEpro]

People just want what they paid for.

My Rolex run so accurately it's actually funny.

My IWC runs -5 no matter what. They don't advertise any accuracy so it doesn't bother me.

[zengineer]

I can get any watch I own, from a modern Rolex to a Chinese Seagull to a Timex to read 0 s/d on my Timegrapher....in a single position at a single state of wind. But change the position or check it again 24 hours later where better movements will shine.