Zenith Defy Inventor Review

Zenith has consistently been one of my absolute favorite watch companies for basically two reasons. The first is that they’re aesthetically daring, not afraid to attempt wild, novel designs. The second is that they prioritize movements, particularly high frequency movements, above all else. The Defy Inventor takes both of those traits and runs with them, being only the second watch to use their entirely novel “Zenith Oscillator” movement design and their Aeronith aluminum foam material.

The Inventor is the sequel to the very limited edition Lab, names that, surprisingly, don’t undersell the horological significance of the pieces. In a weird and new way, what we’re looking at here is a skeleton watch, despite the fact that you can only see a millimeter or so deep into the case.

Perhaps I should say semi-skeleton, as only about 80% of the blue “dial” has been removed, leaving this spoke pattern that’s already familiar to fans of the Defy collection. Beneath it, appearing black in this photo, is a single piece of silicon that is capable of replicating and improving upon the most complex parts of conventional movement design, the aptly-named Zenith Oscillator.

But before we get into how the Zenith Oscillator works (and yes, we will be addressing that), we should take a look at the face of the watch itself. The Inventor continues upon the tradition established by its predecessor, the Lab, as well as the new generation of Defys (Defies?) generally, with bold Genta-inspired designs and skeletonized dials. The Inventor, interestingly, is more aligned with the rest of the Defy collection than its predecessor, thanks to a blue dial and a more restrained use of Aeronith.

From this angle, you can see the coloration of the silicon Zenith Oscillator as well as appreciate the nice sunburst finishing on what remains of the dial. I wouldn’t call the Inventor a beautiful watch, but it is an impressive one and quite fascinating to behold.

Zenith’s large baton hands and their famous star-counterbalanced seconds hand are here, but they really have their work cut out for them maintaining legibility against such a crazy watch face. They do a surprisingly good job at it, backed up by their size and the fact that they’re contrasting with the blue beneath it. This is a good time to point out that the seconds hand is non-hacking, at least on my sample, and it has an incredibly smooth sweep thanks to its ridiculously high frequency movement. While it’s unlikely any truly mechanical movement ever achieves the smoothness of the spring drive, this gets close enough that it makes no practical difference. It beats 36 times per second, nearly five times as fast as an ordinary watch, and amazingly, nearly 4 times as fast as hi-beat watches like an El Primero or GS 9S85. Suffice it to say that, to normal human eyes, it might as well be perfectly smooth.

The Inventor remains legible at night, although given the size of this watch, as well as Zenith’s astonishingly good Pilot watches, I feel that they could have taken this a step further. I probably also would have used a luminescent seconds hand, since it’s the only remaining sign of the watch’s incredibly high frequency once the dial is dark and you can’t see the oscillator working. In my opinion, there needs to be some indication of how insane the watch is at night, otherwise it risks appearing sensible.

Normally I’d save this for the movement section, but since we’re kind of already here, we might as well explore how this wild new design works and what its advantages are. According to Zenith, the Zenith Oscillator is essentially immune to magnetism, extremely resistant to temperature variance, and astonishingly accurate, the latter beyond the capabilities of any purely mechanical watch ever mass produced.

This new movement is the cal. 9100, and it has basically two parts. The first part is “conventional,” which is the part that generates and stores energy–we’ll get to that later. The part you’re really interested in is the Zenith Oscillator, a single piece of silicon that combines the functionality of the hairspring, balance wheel, pallet fork and anti-shock mechanism quite elegantly. Let’s take a close look at it.

One of the interesting things about the Zenith Oscillator is not just how alien it is, but also how familiar it is. For instance, this is the new escapement, essentially the place where the timekeeping happens. Apparently, the teeth of this new escape wheel are made of flexible silicon, which is a first, and very much alien, but at the same time, you can just barely see the tiny teeth that replace the rubies on a conventional pallet fork, made possible by the use of low-friction silicon-on-silicon interfaces. Like any ordinary mechanical movement, the extremely consistent action of locking and unlocking the escape wheel is what keeps precise time.

The Zenith Oscillator, like the watch you’re probably already wearing, also has an equivalent to the hairsprings you’re used to, these extremely fine silicon blades that are highlighted. As the “balance wheel” equivalent rotates back and forth (only six degrees, whereas many ordinary watches are closer to 300), these flex and behave similarly to conventional hairsprings. There are actually three of these, corresponding to the three sections of the “balance wheel,” but one was sufficiently well hidden that it didn’t warrant our attention.

Interestingly, the rotating mass (balance wheel equivalent) spans the entire circumference of the dial and is divided into three separate sections, not too dissimilar to an old-fashioned bimetallic balance. These pairs of thin beams (three sets in all, again, one set was covered up by the dial) form the connection between each section. Effectively, then, this is three separate rotating masses, isolated, to some degree, from each other.

As the Zenith Oscillator has no balance shaft per se, it has no need of a conventional anti-shock mechanism. Instead, each section of the rotating mass has two separate oblong anti-shock mechanisms with a fixed pin in the middle. Presumably, if the oscillator is subjected to a sufficient shock, these oblong sections will be restrained from getting too far out of whack by the stationary pins. The fact that there are six of these, combined with the three separate sections of rotating mass, implies either that Zenith took anti-shock stability extremely seriously, or that the Zenith Oscillator presented new challenges in dealing with loss of accuracy due to shock or vibration. It may simply be the inevitable result of having to secure what is, in effect, an entire balance wheel instead of a single balance shaft.

As is the case with most watch movements, the Zenith Oscillator requires a manual mechanism to speed it up or slow it down as needed, and they went with a form of regulator in the tiny screw highlighted, albeit hidden under a slim portion of the dial. Moving this can change the tension of the oscillator, allowing a watchmaker to fine tune the accuracy. In theory, however, there’s no reason that Zenith Oscillators can’t have a variable inertia rotating mass, like those found in most Pateks, Rolexes, and Omegas, at least to the degree that it has a balance wheel in the first place. That they went with this approach shouldn’t be too surprising, however, as Zenith isn’t a fan of variable inertia balances in general. I also suspect that this would have been very onerous to design if the goal is to reduce the total number of components, since something like Gyromax collets or Microstella screws would have inevitably been discrete components attached to the oscillator.

The Zenith Oscillator, then, is not too difficult to wrap your head around if you already have a decent understanding of conventional movements. To greatly oversimplify, Zenith has combined the pallet fork, balance wheel, hair spring and anti-shock mechanism into a single piece of silicon. At a very fundamental level, it works pretty similarly to what you already know. On a real-world level, however, you’ve never seen anything like this. We’re used to the reasonably slow back and forth of a balance wheel at the back of the watch, easily identifiable to the naked eye. The face of the Inventor, however, does not have a gentle back and forth rotation of a balance wheel–it’s more like the area underneath the dial just vibrates and becomes a blur. The amplitude (the measure of balance wheel rotation) is tiny, but the frequency is enormous, which gives it an unworldly BPH: 129,600. There are hi-beats, then there are arguably ultra-hi-beats like the Breguet 7727, and then there is this. It’s on a whole other level, and it seems to be picking up, since the Inventor, which uses a new version of the Zenith Oscillator, actually has a higher frequency than in the Defy Lab. Amazing.

Since most of the movement is now a single piece of silicon on the front of the watch, there’s not much left to see on the back. Here we are presented with a nice, although very much conventional, automatic winding system and a lovely blue rotor. The system appears to be unidirectional, and this may be the freest spinning rotor I’ve yet encountered. It’s somewhat like the 7750, in that you get a bit of rotor whir (audible only in a quiet room) and a small amount of rotor wobble, which a lot of people really like, I suppose because it’s a tactile and auditory reminder that their watch is mechanical. On the subject, the cal. 9100 is incredibly quiet (aside from the rotor, of course), and you have to put it directly next to your ear to hear it at all. It beats too fast to really appreciate individual ticking, but it’s not quite a solid note yet either. It’s something you’ll have to hear for yourself to understand–to do so, you’ll want to hold the face of the watch to your ear, not the back.

As amazing as the new movement is, it’s not the only interesting thing about the Inventor. There’s also this fascinating Aeronith material, here used on the bezel, and, of course, on the preceding Zenith Lab model. Aeronith is a composite aluminum polymer foam, a material that is said to be substantially lighter than titanium and even a little lighter than carbon fiber. It’s quite porous in appearance, creating a very stark contrast between the polished titanium elsewhere. I appreciate the technology of Aeronith, and I can see the advantage of it in future applications, but I feel that the Inventor is sufficiently crazy already without the strange-looking bezel, so I probably would have chosen a more conventional Defy-styled case for this particular watch. Perhaps a super lightweight Defy Classic Aeronith or El Primero Aeronith would be a more fitting design for the material.

The watch is quite large, at 44mm, and it looks it. I would normally say that I wish it were closer to 40mm, but I don’t think that’s right for this particular watch. For one thing, if you can see how big the new oscillator is, you realize that it’s basically as small as it could be without redesigning the movement, which probably would have been very onerous since the Inventor’s movement is basically a refined version of the Lab’s movement, as opposed to a new movement from scratch. The other reason I find 44mm to be entirely acceptable is because this is a flashy haute horology piece that was never intended to fly under the radar. The Inventor doesn’t want to be your everyday watch, or the watch you wear to your important meetings and so on. It’s a ridiculous, over the top watch worn because you love watches. I slightly criticized the Aeronith because I think it introduces too much of a distraction from what ought to be the centerpiece, the oscillator, but that isn’t a problem introduced by its large size in my opinion.

Fortunately, its extremely short lugs make it more wearable than it at first seems, and its extremely light construction, between the Aeronith and titanium, keep it from becoming a wrist anchor.

The crown has a lovely blue accent to it and is quite bold in its own right. It doesn’t screw down, and because the watch has no date and doesn’t hack, it’s about as simple to set as you could possibly get. The crown is also fairly large, so the watch is very easy to use. It winds extremely smoothly as well, almost effortlessly.

The Inventor is 14.6mm thick, which I suppose isn’t too bad for a modern 44mm watch, but a big part of me wonders why this couldn’t be considerably thinner. The Zenith Oscillator should make this easier than ever. It doesn’t really hurt the watch, because the design is so over the top to begin with, but I’d love to see some hand wound versions of this movement down the road with much thinner cases too. The A384 Revival I just reviewed has a chronograph plus a date and still manages to be 2mm thinner, and that’s using a 50 year old movement.

For most of us, the $17,800 Defy Inventor is not so much of a watch as it is a glimpse of the future. It presents a bold vision for subsequent Zeniths, both in terms of style and, more importantly, substance. It’s pretty clear these days that Zenith views its future as Defy-centric, and that it views radical, high-tech movements as the future the industry. Perhaps almost as remarkable as the watch itself is the fact that Zenith managed to improve upon the Lab in such a short time. The Inventor has a substantially revised oscillator, a totally different escape wheel and an increased frequency, the latter of which is probably responsible for it moving from a 60 hour power reserve to 50.

Zenith promised the watch world that their new oscillator wasn’t some one-off, haute horology exclusive, but rather, that it was a commercially viable path to better watches that their ordinary customer base could buy. While the Inventor will only be made in small numbers per year, it’s a huge step up from the 10 Labs sold, and it demonstrates that Zenith intends to follow through. In that sense, then, one might view the Inventor as merely a path, not a destination, but what a path it is. For those few lucky enough to own this insane watch, they’re getting to enjoy something truly remarkable. The rest of us will have to wait a little longer before we have a Zenith Oscillator in our own watch case, but it looks ever more likely that it will become a reality.

Click here to visit the product page for the Zenith Inventor.

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