Why does the second hand on my Vostok-Europe with the Vostok automatic movement sometimes stutter?
If this is your first Vostok-Europe watch with the Russian movement from Vostok, or even your 15th, you may have noticed that the second hand can stutter sometimes. This can be particularly noticeable from the 10 position before the hour until the hand passes 10 after the hour and starts moving "downward."
Firstly, let's get one thing cleared up before the next few seconds pass on your watch, stuttering or not. This is absolutely normal for the Vostok movements. There is nothing wrong with your watch. It has no impact whatsoever on the timekeeping.
And now a word from our sponsor: Vostok-Eurupe and Vostok are NOT the same company. Vostok-Europe is a younger company based in Vilnius, Lithuania building low-volume, limited-edition, mid- to high-end dive, pilot and sport watches with many models utilizing tritium tube technology. Vostok is the oldest watch company in Russia and makes entry-level to low-mid level watches in high volume. Vostok-Europe uses Miyota, Ronda, Seiko and Vostok movements. Vostok builds the movements that Vostok-Europe uses for a small portion of their overall collection. Vostok has zero to do with the design or construction of the rest of a Vostok-Europe watch.
Now back to our regularly scheduled programming.
So, why does the second hand stutter? The teeth on the second hand gear has a small amount of play to allow for free motion without causing undo tension on the system without effecting accuracy, which allows for a longer service life. This is designed specifically to extend the life of the movement beyond normal expectations by reducing this undue tension. Vostok movements are designed to be workhorses, not necessarily elegant -- a BMW versus a Honda. This can cause a visible "stutter" at times. This can vary a great deal from movement to movement.
This system is exactly the same in the 8215 movements from Miyota.
This has become increasingly pronounced as watches have grown larger and larger in recent years. The second hand has extended to be commensurately longer. It may not seem like much, but adding this extra length can mean 20% or more additional weight on the drive train. That is significant.
This shows up more in the final 10 seconds and first 10 seconds of the sweep because usually when you look at your watch the 12 position is pointing up and therefore the second hand has to climb that part of the chapter ring the most as it is fighting gravity.
You may also notice that if the watch get a sudden shock, even just forcefully putting your hand down on a desk, the second hand will stop entirely for a couple of seconds. Again, this is normal and has no impact on timekeeping. In fact, if it didn't stop, the drivetrain could break. It is similar to the shock resister on the mainspring.
Now, I put forth without reservation that anyone who has a better technical understanding of this, they are more than welcome to correct anything I have incorrect or amplify any points here.
Bottom line, your watch is just fine.