Break in period

[don't back down now]

How long is the break in period on a new Rolex? That is, how long before we can expect a BNIB Rolex to operate within COSC standards? Thanks.

[Art 1]

Originally Posted by don't back down now

How long is the break in period on a new Rolex? That is, how long before we can expect a BNIB Rolex to operate within COSC standards? Thanks.

There is no break in period.

[Watchdog]

I was told at least 3-4 weeks because of the oils in the mechanism. Although, others have said their watches didn't "settle down" for months.

[don't back down now]

yeah, i purchased my 16610 BNIB and didnt have consistent COSC timekeeping until nearly a year later.

[Andad]

Rolex watches movements are tested to COSC spec and only assembled into their case once this has been done. No COSC Rolex would leave the factory unless it was better than -4/+6. Every Rolex wearer applies his or her own influence to this original adjustment based on time on wrist, winding frequency etc and this will have a bearing on the final accuracy of each individual's watch.
IMO a modern Rolex watch that is not within COSC will not correct itself with a break in period and I have not had much success with any of my newer movements correcting time loss/gain with the crown - up - down - sideways - inverted - positions.

[Imtiaz]

My Exp I is sitting in the winder all this month. Just so I can break it in.

All my watches are pretty accurate. Some took a month or so to settle down. Other were spot on from the first day.

[scottjal]

As mentioned it is COSC before assembled or it goes back and gets fixed. I think this mythical break in period is related to how long it sat at the dealer display stopped. Remember sometimes watches sit for months and that time is in addition to the transport and distribution.

Get it back into the routine of running and if it isn't COSC after four months or so take it back and have details on what you are asking for. During that time you should be recording its performance, you want it accurate on your wrist so only record those days and not winder time.

[generic0]

Mine took 1 month of running +13; now it's easily within COSC

[rkb]

Right out of the box my Explorer was a screamer at +9 seconds a day. I had it regulated after 2 months of waiting for it to settle in.

[landroverking]

My lastest one a Sea Dweller was -20 the first day and dead on after day two now about +1.

[padi56]

Originally Posted by don't back down now

How long is the break in period on a new Rolex? That is, how long before we can expect a BNIB Rolex to operate within COSC standards? Thanks.

Well they operate to COSC standards when tested and passed otherwise they could not be called Swiss chronometers.But at the Swiss COSC they test only the bare uncased movement without dial hands or winding rotor .Special ones are put on at COSC they are loaded into magazines wound by a machine Rolex has there own at Swiss COSC owing to the vast amount of movements they test.They are tested by time lapse photography linked to a central computer test is now is quite antiquated.As most modern day movements with a bit of careful regulation could pass the test, If they pass they are shipped back to Rolex who will eventually case and ship out as finished watch.Failed ones are just re-regulated re-oiled etc and shipped back to COSC until they pass.So they should all perform to COSC standard out of the box,but when tested by a machine don't necessarily say it will perform same on someones wrist.But in general its best to wait a few months before any re-regulation should be tempted if needed.

[Sperry]

Mine sat in an Ad for a good four or five years.
It's been spot on, a steady, consistent +8,
until I would the watch. Then it became +7 or +7.5

[Bisquitlips]

I have consistently heard that 30 days or so is about the expected yet unofficial time for the timepiece to calibrate itself and get all the parts running to optimum. Lots of testimony to this and it appears to be a kind of accepted standard.