Adjusting a Russian Wostok 2409A Wristwatch with a Smooth Balance Wheel

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A friend of mine is one of the watchless—people who haven’t worn a watch for years. But he’s intrigued, I can tell, so I offered him a watch from my stash of project watches. He wanted something offbeat and quirky, and in these odd times of ours nothing fits the bill like a Russian wristwatch.

Behold our scuffed and grimy Wostok. It’s a simple watch: just a 2409A hand-wound movement with no date. I bought it from an Eastern European seller on eBay as part of a lot a long time ago, and now it’s time to clean it up for my pal.

The case is chrome-plated base metal with the usual scuffs and dings. Overall, the plating is in respectable shape. The ring of grime around the crystal is gross but par for the course for old Russian watches purchased from Eastern Europe.

The back is rough. These Russian watches usually have the worst case-back design in the history of watchmaking: the 2-piece back with a threaded outer ring. It’s hard to get a tight, firm seal with only a thin threaded ring.

The nicest thing about this watch is the dial. There’s a blue-to-brown sunburst finish that catches the light nicely.

Russian watch companies made watches for export and for domestic use. The export models usually have English writing (e.g., MADE IN USSR or 17 JEWELS). The text on this dial suggests that it’s a domestic model intended for the local market of Marxist revolutionaries.

Here’s another look. I especially dig the hands. All 3 hands are the same color and material—unpainted steel, which isn’t something you often see.

Servicing and Adjusting the Movement

Russian watches are interesting in their own odd way, but they aren’t great timekeepers. The modern equivalent would be Chinese movements that run pretty well for the price but often have wavy traces, slightly erratic timing patterns, and rough-and-ready industrial movement finishing.

The balance wheel and escapement design don’t raise my hopes. There’s an adjustable stud to change the beat rate, which is nice, but there’s no micrometer adjustment for the regulator. There isn’t even a regulator arm to nudge—you just push the regulator arm with the pins and hope you don’t touch the hairspring.

The other weak feature is a flat hairspring. Overcoil hairsprings, for reasons we should get into in a future post, breathe more symmetrically. When the spring expands and contracts, it does so more evenly on all sides. Flat hairsprings, in contrast, tend to develop relatively more to one side. This asymmetry shows up in positional timing. Flat hairsprings will sag more due to gravity in some positions, thus running faster or slower.

This particular hairspring looks like it has been adjusted near the stud, but it develops unevenly. (It’s hard to get a good image of the asymmetry and a couple odd tweaks and bends.) I’m not going to mess with it.

We thus don’t expect great things from this watch, and we’ll hold it to loose standards for accuracy. I’d like it to run reasonably well in all 6 positions, but a Rolex (or even a 100-year-old Illinois pocket watch abandoned for parts) it isn’t.

The watch was cleaned, oiled, demagnetized, and then left to tick away happily for a few days to settle down. The amplitude was great right off the bat (over 310 DU/DD). I nudged the hairspring stud arm to change the beat error, which was high (over 3 ms), to under .2 ms, and I nudged the regulator to bring the dial-up (DU) time close to zero.

So here are the baseline times.

Overall, this isn’t too bad. First of all, the dial-up (DU) and dial-down (DD) times are reasonably close (within 10 seconds), which is enough for a mid-range watch like this.

The 4 vertical (or “hanging”) positions have a maximum variance of 35 seconds, from PU to PR. We could bring these all closer together. The 5 main positions for wristwatches are all but PR, which is the 6th position. If possible, we would like the largest error to be at PR—this is sometimes called “throwing the error into the 6th position” in the old books.

So it’s off to dynamic poising. As we have described in our “how to” series, you start by running the watch at low amplitude. This exaggerates the effects of poise errors. Just find the position where the watch is fastest, and you’ll know that the heavy spot in the balance is below the balance staff when the watch is at rest in that position.

Here are the readings of our Wostok 2409A at an amplitude of around 130 degrees.

The watch is running slow overall, but it is fastest—the least slow—in the PL position. The heavy spot is thus here, at the red pointer.

We correct poise errors by adding weight or removing weight. When the watch runs fast DU, we add weight; when it runs slow DU, we remove weight.

We can’t easily add weight to smooth balance wheels. You can remove weight, but it should be done slowly and carefully—you can’t put back what you took off. I nudged the regulator to make this watch run around -10 DU and then removed a tiny amount of weight.

To do so, I used a small pivot drill (.35 mm) in a pin vise.

By hand, I gradually removed a small dimple of material from the underside of the balance wheel at that point. Slow and steady does it. I removed a tiny bit, checked the timing, and then removed a tiny bit more.

And here’s where we ended up.

This is appreciably better: the vertical positions are all closer to zero, and the biggest error (PR) is in the 6th position.

I hereby declare this watch adjusted. It runs much better than before and probably about as well as a rough and slightly wavy vintage Russian movement is going to run.

Cleaning the Case

Just as painting a room transforms it, simply cleaning a case and replacing the crystal makes it look like new again.

This watch has a chrome-plated case, so there isn’t much you can do to polish it. The plating will wear off if it is polished too heavily, and it will flake off if the case gets too hot. For this case, I simply scrubbed it with a toothbrush and hand soap and then cleaned it in my heated ultrasonic cleaner for around 10 minutes, and that was that.

It looks much better, but it still shows its age like the rest of us.

Like most Russian watches from this period, the case back originally had a light circular grain. Using the tips described in our post on circular finishes, I polished a deeper grain by using coarse emery paper. It looks nice.

Finding a crystal proved to be surprisingly tricky. The case has a channel for the crystal, which you can see between the case top and the reflective inner ring. The crystal’s wall has to be thin enough to fit in this channel. With some trial and error, I found a crystal (32.0 mm, if you’re curious) that I could friction-fit in the case.

The crown was surprisingly crusty. Even after soaking, heating, and ultrasonic cleaning, it had a thick black crust that had to be chipped off by hand.

That’s a sign that you need a new crown. I found a new one in my stash box.

Wrapping Up

This Russian watch is looking sharp.

I wore it for a few days, and it keeps good time, wears nicely on the wrist, and acts as a good conversation piece. So it is off to my friend, and I’m off to my stash, determined to get through the watches I already have before buying any more.