reasonable expectation of accuracy for ETA Tudor

[Jakx]

I have a question. What is the reasonable expectation for a modified ETA Tudor in the Black Bay. After one week of ownership I'm running fast at 6-7 spd. A review by a reputable publication claims Tudor uses the highest grade ETA, which should correspond to a chronometric rate (wrong assumption?).

If it goes beyond that minus4plus6, should I send it back to the AD for regulation?

[T. Ferguson]

The ETA Tudor is easily capable of doing better than COSC spec, once properly regulated. Personally I wouldn't send it to the RSC for 6 weeks over this, but try your AD or find an independent locally that can regulate it. A little fast is no big deal. If you really like your watch to be dead bang on it's a simple matter of "pulling the pin" once a week until your reference time catches up to it, then screw 'er down and off you go.

[Old Expat Beast]

I have three Tudor ETA movements and two of them keep better time* than any of my Rolex movevents (*after being regulated by Rolex). Try laying yours down on its side, winding crown up, overnight, and it should slow down a little. ETAs are, in my experience, more sensitive to overnight positioning than modern Rolex movements, and I can keep mine within a few seconds of dead-on pretty much indefinitely. E.g, I last set my THC last April and it's currently ten seconds fast.

[Ticknaway]

Originally Posted by Old Expat Beast

I have three Tudor ETA movements and two of them keep better time* than any of my Rolex movevents (*after being regulated by Rolex). Try laying yours down on its side, winding crown up, overnight, and it should slow down a little. ETAs are, in my experience, more sensitive to overnight positioning than modern Rolex movements, and I can keep mine within a few seconds of dead-on pretty much indefinitely. E.g, I last set my THC last April and it's currently ten seconds fast.

May I ask what you are using for reference(program or app) I have never checked my watches and it would be fun to do so. Thanks in advance

[T. Ferguson]

Originally Posted by Ticknaway

May I ask what you are using for reference(program or app) I have never checked my watches and it would be fun to do so. Thanks in advance

I use time.gov or time.is

[Old Expat Beast]

Originally Posted by Ticknaway

May I ask what you are using for reference(program or app) I have never checked my watches and it would be fun to do so. Thanks in advance

I just use time.is which is fine for measuring to the nearest second as a reference.

[Jakx]

thank you for the responses! very helpful. After 9.5 days, I'm almost at 60 seconds fast ( a couple of nights with the crown up at night).

[Old Expat Beast]

You might find that it settles down a bit in the coming weeks. My Ranger went from +5 to +1 per day after about two months.

[Friar]

My Ranger went from +4 to -1s/d during the first couple of months. it's quite consistent now. Yours may settle closer to +2 which would be quite good.

I have read too that Tudor uses Top grade ETA movements. While Top uses the same components as those submitted to COSC for testing, they are not tested, and I don't know what would be an acceptable rate to Tudor.

[ttnpb]

A top grade ETA is just as capable as a 3135.

A ton of the other big Swiss names use ETA as their base movements. Omega, TAG, Breitling, and many others use ETAs.

[cab56]

I have two ETA based watches (a Tudor chrono and a Tag Heuer chrono) and a few Rolexes all running within an accuracy of a few seconds a day. I usually wear a watch for a week at a time and when I change watches a week later, I notice that the watch is 15 to 30 seconds off (2-5 seconds per day).

[SearChart]

They can be very accurate, I have an ETA watch of mine regulated to where it runs +4 a week now and it's not even the 'best grade'.

[1William]

I have previously owned two ETA Black Bay watches. One was plus 4 seconds a day out of the box. The second was plus 15 seconds a day. I did not keep the second watch long enough to get regulated. I will buy the new in-house Black Bay very soon and will keep it. I really like it.

[Jakx]

It's settled at +5 now. As long as it stays within chronometric tolerances, I'm happy.

[Blackdog]

First of all, wait for at least 4 weeks before taking any action. In my experience a new watch will slow down a bit and stabilize.

Once it stabilizes take note of the daily rate under your normal wearing habits. With this information in hand you can send it in for regulation.

The ETA 2824 is a very accurate movement and can easily be regulated to better than COSC. My BB is currently running at +2spd.

If you decide to have it regulated it is important that you give your assessment of accuracy to the watchmaker. One thing is the Timegrapher and another the performance in a real life scenario.