What to Know About Mechanical Watch Movements

What to Know About Mechanical Watch Movements

In this article I wanted to take a quick and broad look at watch movements and discuss a few things you all should know about. This isn’t going to be a detailed and technical memorandum on movements, rather a quick guide to help you discern the good movements from the bad ones, and what having a good one offers compared to having a not-so-good one. This article will come with recommendations on how to care for your movement (things you can do at home) whenever applicable. Therefore, more than explaining how a mechanical movement works—which has been covered extensively and better before—I’ll stick to general thoughts about movements. 

Seagull Mechanical Chronograph Movement Source: www.birthyearwatches.com

Hand-wound vs. Automatic 

First and foremost, we should discuss the key difference between hand-wound and automatic movements. Both are of the mechanical variant (as in having cogs, wheels, and springs) as opposed to being quartz (battery-powered and using a quartz crystal to keep the watch ticking accurately) or Mecaquartz (a hybrid between a mechanical and a quartz movement.) Hand-wound movements, as their name might indicate, must be wound by hand more or less each day in order to tick. This is how mechanical wrist watches operated until the invention of the first self-winding movement in 1926 by John Hardwood for Fortis. 

John Harwood First Automatic Wristwatch Source: www.wornandwound.com

A self-winding (or automatic) movement therefore winds itself by way of having a counter-weight rotating inside the watch case as the wrist moves around. It is therefore the action of moving the wrist that winds the mainspring and therefore keeps the watch ticking. Although nowadays most mechanical watches are automatic, brands still make hand-wound movements for those of us who are nostalgic for the age of vintage watches, or because these movements are thinner than the self-winding types (since there is no counter-weight.) It is common for big brand names to put hand-wound movements in vintage re-issues. 

Therefore, having a hand-wound or automatic movement is not a matter of having a better one over a lesser one; it’s more about personal preference: do you prefer to have thinner watches or thicker ones? Would you enjoy winding a movement each day or do you prefer to sit it and forget it? (I love winding my movements as it feels I’m having a deeper connection with it.) 

Hamilton Khaki Mechanical WatchClicker Source: www.watchclicker.com

Power Reserve 

The power reserve of a movement indicates how many hours your watch will keep ticking after being fully wound before it stops. It is advised to fully wind an automatic watch before using it, as being fully charged (for the lack of a better word) will both ensure that the watch keeps running for the duration it is supposed to and also keep better time. Although the balance wheel is what keeps a watch accurate, being fully-wound also helps with accuracy. (I’ve found that a fully-wound watch keeps better time than one that is not.) Each movement comes with different power reserves. The most common for a Swiss or Japanese mechanical movement is 42 to 48 hours. 

There are elements that come at play in making a watch having shorter or longer power reserves. One of them being the frequency of the watch, typically 28,800 beats-per-hour (BPH) or 4Hz. Some brands like Seiko decrease the frequency to 21,600 BPH (3Hz) to increase the power reserve to about 72 hours. Sophisticated movements can have higher power reserves and higher frequencies too, but these movements typically come with higher price tags. Lastly, some brands make it possible to see how much power the movement has by way of adding a power-reserve indicator on the dial. 

Being mindful of your movement’s power reserve is useful for those who like to switch watches regularly. Having 48 hours of power reserve means you can technically put the watch away for two days and it will tick when you strap it on the wrist. Having 72 hours of power reserve means you can confidently put away your watch on Friday night and put it back on Monday morning for work. It will be wound enough to tick and be accurate. 

Grand Seiko Power Reserve Worn and WoundSource: www.wornandwound.com

Protection Against Magnetism 

Let’s face it: the world we live in is full of magnetic fields, from our phones and laptops to our cars and TV screens. Magnetism in watches was probably not as much of a big deal 100 years ago but it definitely is today. Magnetic fields affect a mechanical watch in that it makes the mainspring of the watch (what stores the power and makes the watch tick) stick and therefore the spring uncoils abnormally, making a watch run faster than it’s supposed to—up to several minutes per day! The hairspring can also be affected (the one that makes the watch run accurately) for the same reason. Nowadays, every movement comes with minimal protection against magnetism but it generally is not enough for modern day living. 

At the very minimum, a movement can be certified to be protected against 4,800 A/M (ampere per meter) while most laptop computers generate magnetic fields of 16,000 A/M. So you can immediately see that having superior protection against magnetism is a must. In the old days (like in the 1950s and 60s), brands would put iron cages around the movements to protect them against magnetism (iron is anti-magnetic.) Nowadays, hairsprings made of silicon guarantee protection against magnetism, but it is rare to find such technology in entry-level watches. 

Movements that have silicon hairsprings are more expensive to make and there the watches are more expensive to purchase. Tissot makes reasonably priced watches (under $1,000) that have this technology. As a general rule of thumb, the more you spend on a movement the better protection you have against magnetism. If you do own a watch that runs fast, then I recommend getting a demagnetizer that will allow you to remove the magnetism on the hairspring and balance wheel and make your watch run normally again. 

Rolex Parachrom Hairspring Bob's WatchesSource: www.bobswatches.com 

Protection Against Shocks 

Furthermore, movements should be protected against shocks. Shocks can range from the daily, annoying hitting the top of the watch head on a door frame, hitting it straight on a hard surface, and the eventual drop on the tile floor. Mechanical movements are made of between 150 to 300 tiny parts on average, many of which are microscopic. It’s easy to imagine that they are fragile and need to be protected against life’s daily adventures. Thankfully, modern movements come with built-in shock protections in the forms of the Incabloc and Diashock systems found in Swiss and Japanese movements. 

Some brands go a step above and add metal, plastic, or rubber rings around the movement, between the case. Those made of rubber are particularly efficient at protecting movements against shocks since rubber is a material that absorbs shocks while metal just transmits it to the movement. But again, daily shocks are no longer a real threat to modern movements since the balance wheel is protected. However, if you are into intense sports and activities, you may want to look into watches that come with additional shock protections. The Rolex Explorer 2 is a good example of a watch that has superior protection against shocks. 

Rolex Incabloc Detail Photo Source: www.monochrome-watches.com

Daily Variance 

Lastly, I wanted to briefly touch upon a subject that may upset some of you: daily variance. What I mean is how many seconds your watch gains or loses each day. Daily variance is virtually unique to each watch because it depends on the movement itself—how it’s built and how accurate it is—and you as your daily activities and the types of environment you live in will influence how well (or not) your watch runs. As a rule of thumb, more expensive movements run more accurately and are not subject to changes in temperature or activity. Cheaper movements are however not all of them. 

I’ve had watches with cheap movements that run incredibly well and expensive watches that don’t. And vice versa. But a watch that has a movement that is of the highest quality and well-regulated will perform well under any circumstance and that is a little bit of magic to me. There are simple tricks to keep your movement running more or less accurately that don’t require you taking your watch to a watchmaker. For example: if your watch gains 10-25 seconds per day, lay the watch vertically on the case side, with the crown facing downward at night. If it loses 10-20 seconds per day, lay the watch flat for a few hours so that the dial is put uppermost. 

Although the above doesn’t fix grave damages done to your movement, it does the trick sometimes. At least it does for me. You may not care that your watch gains 20 seconds per day but that is something that I’m sensitive to. I like to have accurate watches and this often means paying a little premium for it. (In both having higher quality movements or getting cheaper ones serviced more regularly.) 

Watch on a Timegrapher DIY WatchClubSource: www.diywatch.club

Final Thoughts 

There you have it. As promised, I stuck to general thoughts and information to get you started on creating a closer relationship with the movement that ticks inside your watch. You may even find it enjoyable learning more about what ticks inside your watch and what causes it to gain or lose time, and what you can do to protect it against shock and magnetism. Mechanical movements are marvels of technology and an integral part of the watch collecting experience for many of us. 

Featured image: www.web-horloger.fr

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