AP Caliber 3126/3840 vs. 4401

[marc2828]

More of a technical/reliability question here.

I was wondering what the consensus is on the newer fully in-house chronograph AP 4401 caliper. I asked a watchmaker and he said the older sandwich 3126/3840 is a better movement. Seems odd to me. I have heard the older 44mm offshores that get sent in for service to AP get a new 3126/3840 movement. Does anyone know how much and how long that service takes? And if the replacement is more reliable/better?

In terms of specs, the new AP 4401 has 40 jewels, 70hr reserve, and 28,800 frequency and totally in-house vs. the older 3126/3840 with 59 jewels, 50 hour reserve and 21,600 frequency (less accurate) with half not in-house.

any replies or thoughts are appreciated.

thanks,
Marc

[Reign]

4401 is better but not by leaps and bounds.

The older modular chrono is more delicate and has a hard time with being worn hard for a ROO.

New movement is better to look at, very accurate but takes ages to wind and known issue of sub dial hand slippage in a stopped position


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[eonflux]

I had a forged carbon 44mm as a daily driver and I used the chronograph frequently with no problems. Loved the overall esthetics of that watch.

But I would have preferred an integrated chronograph with a column wheel, and that's one of the reasons I let it go.

A 43mm with the new movement, a ceramic bezel, FC case, and all-black dial would be awesome!

[neal.jy]

I’ve been really enjoying my ROC with the 4401; the flyback mechanism is very useful when I’m timing things, and it’s been extremely accurate (+1 to 1.5 sec/day). As mentioned above, some people have reported an issue with the minute counter subdial hand slipping, but I personally haven’t seen that yet.

Power reserve of 70hrs is also fantastic, even without being super active and switching between different watches, I haven’t had it stop yet.


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[Mercutio]

I‘ve struggled without same issue when I registered my interest with AP for the 38mm ROC. User pjm1289 shared some interesting thoughts here, https://www.rolexforums.com/showthread.php?t=869407

(This discussed the differences vs. the FP 2385, but hopefully can still serve as a data point)

Hope this helps. Ultimately, in my case, my small wrist size also played a huge role in gunning for the old caliber, the new movement is very chunky.

[marc2828]

Thank you for the replies. I called AP service today. Here is what I found out. Sending in the older 44mm ROO you have 2 options, service or replace movement. They only replace the 3126 part and it is now a 3126.2. I imagine they service the 3840 part. Cost is $1800. If you choose to replace or service the 3126, cost is the same, but wait time is different. Replace is about 3weeks, service is 6weeks.

Differences: I was told the new 3126.2 has a larger balance wheel, a bigger barrel, and a 70hour reserve vs 50. The date window is slightly closer also I am told, and the movement looks different on the clear case back.

This is what I was just told. Hope it helps.

[Socomo]

Thank you for the information, Marc.

[CactusTreeFiddy]

Originally Posted by neal.jy

I’ve been really enjoying my ROC with the 4401; the flyback mechanism is very useful when I’m timing things, and it’s been extremely accurate (+1 to 1.5 sec/day). As mentioned above, some people have reported an issue with the minute counter subdial hand slipping, but I personally haven’t seen that yet.

Power reserve of 70hrs is also fantastic, even without being super active and switching between different watches, I haven’t had it stop yet.


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Is the 4401 actually known to be fairly accurate?

[neal.jy]

Originally Posted by CactusTreeFiddy

Is the 4401 actually known to be fairly accurate?

I don’t personally have enough of a sample size to say definitively, but my chrono with the 4401 has been extremely accurate. I just reset it this morning, it gained 10 seconds over the past 7 days.. +1.5s per day is pretty good in my books


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[marc2828]

Originally Posted by eonflux

I had a forged carbon 44mm as a daily driver and I used the chronograph frequently with no problems. Loved the overall esthetics of that watch.

But I would have preferred an integrated chronograph with a column wheel, and that's one of the reasons I let it go.

A 43mm with the new movement, a ceramic bezel, FC case, and all-black dial would be awesome!

Just pickes this up...

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[marc2828]

Notice the date on this ROO that was serviced. Looks way larger and closer.

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[marc2828]

And....

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[J.T.]

I sent 2 of my 3126 in for service and had movements updated to new version. I can see zero visual difference when comparing side by side and front/back to other 3126 Offshores I own that are not updated.

[J.T.]

The visual you are seeing above is just the angle the photo was taken

[marc2828]

Ok thank you. That helps....I will wait.

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