Movement Overview

[light94]

I've been reading a ton of threads on movement differences but am still slightly confused. Can someone tell me if these statements are right/wrong?

1. The A21J is one of the cheapest and most reliable movements. The main drawback is that it's a low beat movement so the second hand doesn't sweep as "smoothly" and instead "ticks" more. This is a good, super low budget movement.

2. The only options for a chrono are A7750 or quartz. The A7750 is far from a super rep and has reliability problems, especially in the versions with the seconds subdial at 6. The ETA7750 is a much better option.

3. The A2824 and A2836 movements are both very good copies, and are almost always as good as their ETA counterparts in terms of movement reliability and longevity. The only downside is some gen parts may have trouble fitting asian movements if you're interested in modding. If you have no interest in modding, the asian versions are the way to go because they're cheaper and just as reliable.


Also, two questions:

4. What exactly is the difference between the 2824 and 2836, and is one better than the other in terms of overall reliability? They seem to have the same jewel count, beat rate, etc.

5. What's the "DG A4813" movement? How does that compare to the other movements I listed above?

 

[blind-m]

2836 is a day-date movement
2824 is a date movement
Otherwise the same.

4813 is a 21J

 

[light94]

2836 is a day-date movement
2824 is a date movement
Otherwise the same.

4813 is a 21J

Care to explain the difference b/w a day-date movement and date movement? I'm a noob, I know.

Is a 4813 the exact same as a 21J or just similar? What's the reason for the different names?

 

[d4m.test]

The A21Js can differ drastically in quality depending on where they are made/ put together but generally are great value for money as you can purchase one new for like $20. The 21Js tick 6 times a second as appose to the ETAs and clones that tick 8 times a second. If a 21J breaks its cheaper to replace the whole movement than get it fixed.

The DG1813 is a high beat version of the 21J so it ticks a more desirable 8 times a second as appose to 6. I think it can be hard to source some of these movements if yours decides to die though so be careful.

Also I dont think A7750 are to unreliable these days as long as you look after them.

Hope i helped you out, if ive made any mistakes anyone feel free to correct me im pretty new to the game too. :cheers:

 

[blind-m]

There are a number of different 21J movements. I don't know the difference.
This thread goes into the differences:

http://forum.replica-watch.info/vb/showthread.php/rolex-wiki-page-109932

The 2836 day-date has the ability (whether or not its used on a specific watch) to display both the day of the week and the date.

The 2824 is date only (again whether its used on a watch or not).

 

[cwazy1]

There are a number of different 21J movements. I don't know the difference.
This thread goes into the differences:

http://forum.replica-watch.info/vb/showthread.php/rolex-wiki-page-109932

The 2836 day-date has the ability (whether or not its used on a specific watch) to display both the day of the week and the date.

The 2824 is date only (again whether its used on a watch or not).

partially correct... the two movements vary in their stem height, thus some watches use one, and some use the other.

the sw200 is a 2824 dimensions and the eta2836 is to the a2836.

 

[cwazy1]

The A21Js can differ drastically in quality depending on where they are made/ put together but generally are great value for money as you can purchase one new for like $20. The 21Js tick 6 times a second as appose to the ETAs and clones that tick 8 times a second. If a 21J breaks its cheaper to replace the whole movement than get it fixed.

The DG1813 is a high beat version of the 21J so it ticks a more desirable 8 times a second as appose to 6. I think it can be hard to source some of these movements if yours decides to die though so be careful.

Also I dont think A7750 are to unreliable these days as long as you look after them.

Hope i helped you out, if ive made any mistakes anyone feel free to correct me im pretty new to the game too. :cheers:

well explained.

21J's come in many flavors... the DG2813 is pretty good, others, can be iffy.
DG4813 is just a high beat 21J. same construction, different gear train. I fuckn hate 4813, never had any luck with them.

7750 has many variations.. most common are sec@6, @9, @12, and @3.

seconds @ 6 is the most problematic. these are common in modern daytonas and IWC portu's.

seconds @ 12 is much less problematic.. these are available in the APROO's and the newer models are fully jeweled, so those are pretty safe.

seconds @ 9 is standard, no worries there

seconds @ 3 is fully jeweled and comes on a few reps, they're very safe as well because its fully jeweled xfer plate.

 

[mclarendude]

Just wanted to add:


There's also the ETA 2846, which is basically, the same as a DG2813. Runs slower, at 21k beats per hour, its used more on "vintage reps" like the Rolex Submariner 1680's and watches along those lines. I think the DG2813 (the 21J ticking at 6 ticks per sec) is made based on the 2846, but not sure.