Breitling Superocean 21J vs. ETA2836

[zinberg]

Is there a way to know the difference between the two movements? I have a GTA swiss watch and I noticed that when I shake the watch there's a distinct sound almost a ball/spinning sounds that last for a few seconds. For my 21J this sounds is missing. Can anyone shred some light on this?

Thank you.

[alligoat]

The spinning sound is your rotor. This is what keeps an automatic movement wound. But you can't really tell an eta movement from an asian by the sound of the rotor. I have the SFSO w/ the asian 21j movement and the rotor is fairly loud. But I just bought a genuine Sinn 303 (modified swiss 7750) and the rotor in it is even louder than the 21j asian in my SFSO. I just love to give the Sinn a shake and listen to the rotor spin. Generally, it's been my experience that the eta's are quieter than the asian 21j's, but the only way you can really tell which movement you have is if you open up the watch and take a looksey.

And don't forget with rep watches, be it the swiss eta movement or the asian 21j, there's really no guarantee as to how good a shape your movement is in. The eta's are basically surplus and could easily be in need of a service and the asian 21j's might be just as dirty.

[Pugwash]

Is there a way to know the difference between the two movements? I have a GTA swiss watch and I noticed that when I shake the watch there's a distinct sound almost a ball/spinning sounds that last for a few seconds. For my 21J this sounds is missing. Can anyone shred some light on this?

Thank you.

Some rotors are unidirectional. They can really spin in one direction as there's no winding happening. Bidirectional rotors don't spin as freely as they have to wind in both directions.

Bidirectional is better, but even the genuine 7750 and 7753 movements are unidirectional.

Will that do?