209. Why are Rolex watches able to spin smoothly or what do jewelry inspectors look at to tell the difference between a fake and a real Rolex watch?
A real Rolex watch has a sweep second hand that appears to move steadily around the watch face. A fake, like most other watches, has a second hand that moves with a jerky motion, advancing a little bit each time the balance ring completes one half of a cycle. However, a reader has informed me that even a real Rolex moves its second hand in tiny steps—they're just very small. If you look closely, he writes, you'll see that the second hand makes 5 tiny steps each second. Evidently, the hand-advancing mechanism steps at a higher frequency (5 Hz) than in most other watches (1 Hz). These tiny steps are hard to see so the hand appears to move smoothly. I was relieved to hear this news because the balance ring mechanism is inherently jerky and it's hard to imagine a balance ring-based watch that avoid the jerkiness.