are the 21j (Asian) movements really this bad?

[ilovetrains]

So I made my first rep order for 2 Noob factory Rolex reps. One a classic Sub and the other a Deep Sea. Both with the 21J as most criticism I heard was on longevity of the movement and noise, which neither truly bothered me. I received both models, and immediately noticed a problem with the deep sea. It simply will not keep time. It loses at least 15 minutes each hour, sometimes more, sometimes less. the date wheel jumps quite a bit (as if truly loose, not just mis-aligned.)

Oh well I think, I will send it back, the SUB seemed to be good. Wait a day. now it loses time, in about 5 minute increments, randomly. I looked t it last night and it was 5 min slow. Weird, had been perfectly accurate for 36 hours. No worry, set it forward. Kept an eye on it was fine, fine, fine, and then suddenly 5 minutes slow. I had checked it probably less than 30 minutes prior. Just suddenly lost 5 minutes.

So now I am 0 for 2 on the 21J.

My question is, is the movement really that bad, or are the examples I got just really bad?

[Furu]

My only A21j keeps time and overall it works well, but still far from the exactness of my ETA's.

Sometimes when i screw down the crown the A21j movement is still winding and it will stop after about 20 sec. But with knowledge of that, this is no problem.

You've most probably had bad luck! But don't fear, and there's always ETA.

[plaifender]

funny enough I've had about 4 watches with asian "21j" movements and all of them have kept perfect time. I only have one now (chopard GTXL) that remains in my collection since I've made an active decision to only buy Gen ETA movements now

[automatico]

"My question is, is the movement really that bad, or are the examples I got just really bad?"

Imho...the movements are basically good designs...ST6, ST16, NN38, DG2813 etc but many them suffer greatly after leaving the factories. It is true that some duds will leave the factory but I bet most of the troubles are caused by careless storage and handling after leaving the factories.

How many have you seen with fingerprints and various UFO fibers, (hairs?) etc all over them?

I took the time (wasted the time?) to clean and oil a few and so far they are running just fine. The most common trouble I have seen is 'stopping for no reason'...the reason usually being grit etc in the movement.

Consistency is important...if it gains or loses 1 minute a day every day it can usually be timed to a better rate.

If it gains 1 minute one day and loses 5 minutes the next...something is wrong.

If it gains or loses 15 or 20 minutes (or more) every day...something is wrong.

When one of these movements does not keep good time, the usual fix is to replace it...after making sure the replacement is clean and keeps time.

[Watchmeister]

The movement design is fine. But Asian 21j covers a whole host of different movements being assembled in different places. They may be fine or the issue may be assembly with proper lubrication or crappy parts or both. I have found there is a larger "crap shoot" element.

[ilovetrains]

When ordering, the 21J was litterally half the cost (or less) of the same watch with Asian clone 2836 movement. From what I am hearing, the problem is not the movement's themselves, but in the installation etc. So why bother going for the more expensive movement?

I should note that in this case, the only difference listed is the movement, the crystal etc are supposedly the same.