Should old COSC watches come within today's specs?

[crimscrem]

It's my understanding that COSC specs have changed over the past decades. I'm not quite sure what they used to be and how they've changed, but nevertheless, they've apparently changed.

So, let's say you have an older watch from the 70s or from whenever Rolex started getting their watches certified. We know that as part of the Rolex service, they test it to make sure it's within COSC specs. Do they test it for the COSC specs of today (-4 to + 6 seconds)? In other words, to the extent COSC standards were more lax in the past, will the watch now run more accurately after a modern day Rolex servicing?

My initial thought would be that unless mechanical parts or movements are changed that they would not run as well as the modern watches. But then what kind of COSC testing do they do upon service?

[GoldenBear]

I would think it's like a classic car. They don't have the crash proof bumpers or the 3-point seat belts that are required now. Also, if they keep upping the COSC standard, older watches shouldn't be punished because they lack today's technology and materials. Just my guess.

[crimscrem]

Originally Posted by GoldenBear

I would think it's like a classic car. They don't have the crash proof bumpers or the 3-point seat belts that are required now. Also, if they keep upping the COSC standard, older watches shouldn't be punished because they lack today's technology and materials. Just my guess.

I think that makes sense. But then does Rolex go back to the older COSC standards and test the watch for that variance before certifying that the watch is in good working order? That's where I get confused. I should have asked the watchmaker at my AD.

[Tools]

I don't believe that once your chronometer gets it's COSC test and can then have the fancy wording on the dial, that it is ever tested agaiin..
The COSC tests and Lab have only been in existence since 1973.

Here is an excerpt from a Chronocentric article:

While competitive chronometer testing took place at the Observatories in Neuchâtel (1866-1975) and Geneva (1873-1967), testing of large numbers of watches intended for public sale was conducted by the independent Bureaux officiels de contrôle de la marche des montres (B.O.’s) established between 1877 and 1956. Between 1961 and 1973, “a chronometer [was] a precision watch, which [was] regulated in several positions and at different temperatures and which had received a certificate [from the (“B.O.)”]. Collective certificates, rather than individual certificates, were usually issued. The 1961-73 standard required a mean daily rate in five positions of -1/+10. In 1973, the B.O.’s came under the C.O.S.C. which specified a daily rate of -4/+6 sec.


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[crimscrem]

Originally Posted by Tools

I don't believe that once your chronometer gets it's COSC test and can then have the fancy wording on the dial, that it is ever tested agaiin..
The COSC tests and Lab have only been in existence since 1973.

Here is an excerpt from a Chronocentric article:

While competitive chronometer testing took place at the Observatories in Neuchâtel (1866-1975) and Geneva (1873-1967), testing of large numbers of watches intended for public sale was conducted by the independent Bureaux officiels de contrôle de la marche des montres (B.O.’s) established between 1877 and 1956. Between 1961 and 1973, “a chronometer [was] a precision watch, which [was] regulated in several positions and at different temperatures and which had received a certificate [from the (“B.O.)”]. Collective certificates, rather than individual certificates, were usually issued. The 1961-73 standard required a mean daily rate in five positions of -1/+10. In 1973, the B.O.’s came under the C.O.S.C. which specified a daily rate of -4/+6 sec.


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I guess from a personal standpoint, your post answers my question as to what the variance on my watch should be (-4/+6). I'm surprised that the standard remains the same since 1973.

I thought though that as part of the service that they watch how your watch performs over the course of a few days (i.e., is it running too fast or too slow).

[padi56]

Originally Posted by crimscrem

I guess from a personal standpoint, your post answers my question as to what the variance on my watch should be (-4/+6). I'm surprised that the standard remains the same since 1973.

I thought though that as part of the service that they watch how your watch performs over the course of a few days (i.e., is it running too fast or too slow).

And before the Swiss COSC was formed as it is now there were Observatory testing and competitions to a much higher standard

And during the entire 23 years of testing, 5093 wristwatches were submitted for certification, and only 3253 were passed, about 64%. Just a few manufacturers participated, and only Omega and Patek did so every year. The others were: Rolex, Zenith, Longines, Movado, Vacheron & Constantin, Ulysse Nardin, Cyma and Favre-Leuba, along with numerous independent professional watchmakers.That was until Seiko come on the scene and started to wipe the floor with the Swiss watch industry.Only 2 brand in the + 23 years of the competitions submitted movements of serial production for retail sale(Seiko and GP).All others were specially made movements just for the competition.and it was ended by the swiss in the 1970s after two straight wins by the Japanese straight off the production line Seiko Grand.

Seiko first entered the competition,with watches from all over the world.Including most of the Swiss high end brands.For a much higher standard than the COSC,the Astronomical Observatory Authorisation Chronometer Standard.Out of many watches summited only two passed this test Seiko Grand just a production model, and Giraud Peregaux a specially build for the test model.And in the late 60s there were only two companies, who could sell watches, passed astronomical observatory authorisation Chronometer in those days. ---Seiko and Giraud Peregaux.As the Japanese had dominated in the late 60s and the two preceding events, in 1972 some Swiss watch manufacturers demanded the end of the observatory competitions,and it was ended in 1973,thats when COSC was founded.

[Tools]

Originally Posted by crimscrem

I guess from a personal standpoint, your post answers my question as to what the variance on my watch should be (-4/+6). I'm surprised that the standard remains the same since 1973.

I thought though that as part of the service that they watch how your watch performs over the course of a few days (i.e., is it running too fast or too slow).

Most Vibrometers used to time a watch after a service use a rotatable head where the watch attaches. This movable head can allow the watchmaker to move the watch to the 6 different positions: Crown up/down/left/right/ and dial up/down.

Now whether the watch is actually timed in all these positions may be another story..

This does not replicate the COSC testing, but it will show the deviation in the different positions and many times they are timed in the crown up, crown down and dial up (3 positions) and then set at a median figure.

[SPACE-DWELLER]

It's much a matter of maintenance and regulation. Well maintained (= regularly serviced) and properly regulated, your 17 year old DJ could easily run within COSC specs.

[padi56]

The current COSC test (Contrôle Officiel Suisse des Chronomètres},for Swiss watches dates from around 1973 when it went independent as a non profit organisation.And most Rolex made in the last 50 years could easily meet the standard.Same could be said for nearly all modern day mechanical movements with a bit of careful regulation.But the European DIN, or the Japanese equivalent for mechanical or Quartz is too a higher standard than the Swiss test -2 +4 for mechanical.

[bwalkerVintage]

My 36 year old GMT runs within COSC specs.

[mike]

I don't have a vintage piece that's outside COSC specs. As stated serviced and regulated there's no reason why these watches can't preform with modern counterparts.

These are +1,







Plus 2,





LESS than +1,



I could go on....the important thing is take care of them.

[padi56]

Mike your pictures are a credit to you and some great old timers there and agree the 15XX series movements will take some beating.IMHO still the finest Rolex has ever made well over engineered and seems to run forever.Even my 1922 Unicorn still runs just a few seconds over the COSC spec.