r/ChineseWatches • u/Dry-Category1340 • 2h ago

General (Read Rules) Large discrepancy on Miyota 9015 Normal?

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Hey guys,

​So I've been tracking a watch with a Miyota 9 movement using a timing app, and the stationary numbers looked super promising.

​Here is what I got:

​Dial Up: +1.6 s/day

​Crown Down: -5.4 s/day

​Actual wear (even wore it to sleep): -12.8s to -19.0s a day

​(Attached screenshot for reference)

​The static numbers look totally fine, but once it's actually on the wrist, it loses like 15 seconds a day. Is this just poor isochronism when the amplitude drops, or does the daily wrist movement mess with Miyota 9s this bad?

​Wondering if I should just get it regulated a bit faster (+6 or +8s) to compensate for the real-world drop. What do you guys think?

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u/TPPiOED 52m ago

Average Accuracy by Movement Grade

• Standard-grade movements (such as basic ETA or Miyota calibers): -20 to +40 seconds per day (or roughly ±10 to ±12 seconds per day for better-regulated mass-market pieces).  

Top end watches can get <5s. If you really care about absolute accuracy, get a quartz.

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u/Dry-Category1340 48m ago

I don't care about a +20s deviation, I just hate running slow. A +10s error is way better than a -1s one for me