what's the accuracy on your non COSC Rolex ??

[gettocard]

Let's say for example a ND Sub no COSC. Are you happy with your accuracy so far ???

[padi56]

Originally Posted by gettocard

Let's say for example a ND Sub no COSC. Are you happy with your accuracy so far ???

Fact all Rolex movements since the 15XX series are more than capable of COSC standards.So are many others with a bit of careful regulation myself have a Alpha manual wind chronograph cost around $65. Which is a Chinese Seagull S19 which is a copy of the old out of production Venus 175.Now off to my watchmaker friend and his timing machine.This will sort the men out from the boys,well the first position he timed was dial up.The graphs banking was pretty well even, and showing + 5.07 seconds per day. Now this is a good sign, he only ran 100 beats for each run since after 100, the principle of cancelled returns starts to take effect.

Next position was logically the dial down position.,I notice now that the balance is running very slightly erratic and showing + 8.01 seconds per day .Now crown up, probably the least important position showing + 7.25 seconds daily, and a very even graph.Now the most important position crown down, now in this position gravity has it's greatest effect on the balance wheel.I would expect it to speed up a bit,in this position graph shows + 10.seconds daily,with a perfect strait line graph,this is excellent considering price of watch.Overall it was running at just over Chronometer spec at + 7.65 seconds daily,with excellent isochronous.So out of the box it was tested and running very close to COSC specs.Now a new watches tend to run a bit fast till the oil circulates around all the moving parts.But with a bit of regulation this watch has been wound daily for just about 3 years still running well inside COSC spec.Fact nearly every mechanical movement made today,with a bit of careful regulation could meet the COSC standard.

But while a Rolex movement is made to be a chronometer whether it states on dial or not other brands non COSC movements have to be made to be.And may need quite a bit of regulation in there life to keep them there.But for how long well time will tell on that one, some movements what some call the low mid end in the watch world, can turn out some quite remarkable results.But a Rolex is a Rolex and and its got to be one of the finest long lasting accurate movements on this planet today.

[DSJ]

Nice post Padi. You're right, while chronometers must run within chronometer specifications, all watches should keep time!

[karmatp]

My old non-cosc sub kept better time than my cosc cert. one, same movement anyway, it's just marketing if you ask me. I could care less if my watch is cosc certified, as long as it keeps good time, I'm happy.

[mike]

Just took this out of rotation for a while. +1 second.

[3bee]

I'm very happy with the accuracy of my 1997 Sub ND which is +0.5 secs per day!

[Mrdi]

We have a few in the house and the Air King is the most accurate!

[Lion]

Yes, I am happy with the accuracy of my non certified SS SUB NO DATE(14060M). I have had it a week and it is running 1 second fast each day. Now compare that to my Zserial# 2007 GMT-II PEPSI(COSC certified) which runs 5 seconds fast each day. So this tells me that both movements are within the correct parameters regardless of COSC status!!!

[ArizonaHD]

All of my Rolex keep time within COSC spec, even non COSC models and Tudors Pretty much every mechanical watch I own could meet spec right now (even the Japanese brands), the real key to accuracy is a good watchmaker.


IMO after the watch is serviced it is no longer COSC.

[yannis]

It shouldn't be a surprise these watches are running as good as COSC certified ones!