It is always exciting when a brand develops their own watch caliber. For the past couple of weeks, I have had the pleasure of handling the new Oris caliber 400.

I have put it through its paces, partially disassembled it, and analyzed some of the concerns raised by collectors since it appeared in the Aquis this past year. This won’t be a review of the watch and I won’t give a rundown of the published specs of the movement, although you can find those in our Caliber Guide. This is a thoughtful analysis by a watchmaker (myself) of this movement. (Pictured top – 3 part PR kit from Oris with VR headset, movement, and complete watch)

When Oris announced the caliber 400 one of the first things that I noticed was the interesting way they chose to attach the oscillating weight. It jumped out at me right away because so many brands are using ball bearings these days and this movement clearly did not. It also had me a little nervous because a two-dimensional picture doesn’t tell the whole story. Depending on how the clip interacted with the movement it could have been disastrous. They did it right. The oscillating weight is reminiscent of so many of the early automatic weights from the 1950s and 60s that have survived until today. The weight is rigidly connected to a tube which slides over a post that is fixed to the watch movement. The clip (as artistic as it is) merely keeps the weight from rising up and it does that job beautifully.

Oris caliber 400
Fig 2 – Oris caliber 400

When the three-part press kit arrived from Oris complete with VR goggles, a fully functional movement encased in acrylic, and the Aquis Date Calibre 400, I started as Oris intended with the VR experience. Much to my surprise, the VR experience was very immersive and entertaining. If you find yourself at an Oris dealer I would recommend you ask to try it out. It is definitely fun! After a quick look over the watch, I started looking the movement over. I knew right away I wanted to analyze some of the concerns raised by collectors, but I also wanted to see what they may have missed.

Overall, I truly feel that the quality of the caliber 400 is better than should be expected for the first in-house caliber from a brand. It isn’t perfect, but it is a well-built machine. The finish is quite industrial which is fitting for a movement that will probably prove to be a work-horse in the Oris lineup. I believe the movement will be durable. One of the specific items that jumped out at me was the detent mechanism for the winding stem. Usually, the stem is held in place by a single post riding in a channel in the stem. The caliber 400 features two posts, opposite each other, one secured with a screw and the other held in place with spring tension. This double mechanism reduces the likelihood that the stem will come out of the watch accidentally. I believe this watch will meet the challenge of Oris’ impressive 10-year warranty.

Oris caliber 400 Technical Review
Fig 3 – Arrows indicating how to release the stem

From the watchmaker’s perspective, it even looks like they designed the caliber 400 with after-sales service in mind. Often brands don’t think about what will happen when the watch needs to be serviced, but in this case, it is apparent that the needs of the watchmaker were considered. The watch comes apart and goes together easily. Anything that is out of the ordinary is clearly marked to aid the watchmaker in his service. For example, with two barrels it can be more difficult than normal to figure out how to release the power stored by the mainsprings before servicing the watch. The click is clearly labeled with an arrow. Also, the double release for the winding stem (a feature exceedingly rare in watchmaking) is also well marked. Most watches require you to either turn a screw or depress a button. This watch requires both and is marked with an arrow indicating you must loosen the screw and another pointing to the button to release the spring tension. Servicing these watches should be straight forward for any watchmaker.

Oris caliber 400 Technical Review
Fig 4 – Arrow indicating how to let down the power


First and foremost a watch must keep time. Before opening up the watch or dismantling the movement, I put it on the timing machine to observe its performance. The watch had an average daily rate of +5 with a maximum deviation between positions of 6 seconds at full wind.

Satisfied with those numbers I decided to put the watch through a full Quality Control Timing Check while I examined the movement in more detail. For the next 7 days, I observed the watch’s performance testing both timing and the automatic winding system. The test consisted of the following:

Day 1: Fully wind the watch by hand and place Dial-Up
Day 2: Crown Left
Day 3: 1 RPM Final Test Simulator
Day 4: Crown Left
Day 5: Dial-Up
Day 6: Dial-Up
Day 7: Watch stopped.

Over the first 5 days of the test, the watch averaged just under +5 seconds per day, however when the watch was on the Final Test which simulates the constant motion of a watch on the wrist the watch neither gained nor lost any time. During the 6th day of the test as the watch wound down, the watch gained 17 seconds.

Oris Caliber 400 Rate Results

Average (5 days) +4.8 seconds/day
Average (6 days) +6.8 seconds/day

This 7-day test brought to light one of the first complaints I have heard from individuals who have purchased this watch and that is that they don’t seem to get the full 5-day power reserve as advertised by Oris. Before addressing this I think it is important to note that it takes a lot to fully wind a double barrel (5-day power reserve) watch. When manually winding this watch it takes more than 100 turns of the crown to fully wind it up, where most watches would be fully wound with about 40 turns of the crown. In fact, I fully wound the stand-alone movement and observed that it ran for 125 hours before coming to a stop so we know that the watch is capable of storing enough energy and operates with sufficient efficiency to deliver the full 5-day power reserve with a little left in the tank. This is important because it means that any issues with power reserve are a result of insufficient winding. Unfortunately, the quality control test demonstrated that a day of standard motion is not enough to fully wind the watch. It is however enough to both maintain and add approximately an additional day of reserve to the watch (your results may vary depending upon your level of activity.) Having run down 48 hours, one day on the final test only wound up the watch enough for it to run for 95 hours after removing it from the final test. But why?

Oris caliber 400 Technical Review
Fig 5 – The oscillating weight mounted to the movement

It seems that the automatic winding mechanism on this watch is not as efficient as it needs to be (based both on my tests and on the experiences of some other owners.) There are two key factors in the design which contribute to this. First, this watch has a unidirectional winding system; winding in one direction and idling or “free-wheeling” in the other direction. Plenty of watch brands and horological textbooks indicate that unidirectional systems are equally as efficient as bidirectional winding systems but they have the added advantage of being simpler and made up of fewer parts. 1 If this is the case, why do so many brands spend the extra money on more complicated bidirectional winding systems? Clearly, there must be advantages to a bidirectional winding system. Second, the oscillating weight is light. In an effort to reduce the height of the movement, it would appear that Oris has chosen a weight with limited mass around its perimeter. The weight does have a larger diameter allowing it to achieve the same moment of inertia as a smaller weight using less mass, but this weight falls short.

Oris caliber 400 Technical Review
Fig 6 – Comparing the oscillating weight of the Oris Caliber 400 (bottom) with the ETA 2824 (top)

If you wear the watch daily this won’t be a problem. You can take it off on Friday night and it will still be running on Monday morning and by mid-week it should be back up to full wind. If however, you plan on wearing it for just one day and then waiting 4 or 5 days and wearing it for one day again, you will probably find it stopped.

Hand Setting

The next concern that has been raised by owners of the watch is the hand setting. When you pull out the crown to set the watch the minute hand jumps (as much as 3 or 4 minutes) and even more concerning is that sometimes when you push the crown back in after having set the time the minute hand will jump again (about a minute.) This is frustrating! After meticulously setting the time, making sure that all the hands are in sync, only to have the minute hand jump can be infuriating.

Oris has indicated that this is a result of design decisions made to accommodate the 5-day power reserve and the two barrels and that the hand jump can be avoided by turning the crown slightly backward before pushing in the crown. They are right about the work-around. If, after setting the time, you turn back the crown a little (not enough to move the hand) before pushing the crown back in the hand will not jump. All of this has nothing to do with the 5-day power-reserve or double barrels. This is a result of the engagement of the intermediate setting wheels. On most watches when you pull out the crown the sliding pinion moves straight in to engage with the setting wheel, or it may swing in, but on an arc that transects the center of the setting wheel’s axis of rotation (red circle). In this watch the arc is too shallow and the intermediate setting wheel swings in on an arc that transects the teeth of the setting wheel (blue circle) which causes the wheel to rotate as the two wheels engage or disengage. (This is much easier to see in the video) The rotation can be mitigated by having a narrow or shorter tooth profile.

Oris caliber 400 Technical Review
Fig 7 – Setting mechanism of the caliber 400. The blue circle shows the arc of the intermediate setting wheel. The red circle shows the ideal arc for the engagement without rotation.

I believe this problem could have been avoided during the design phase and can probably be resolved (or reduced) with some component updates. Ideally, you would accomplish this without having to redesign the mainplate. Technical updates are common when a brand releases a new caliber. They rarely get discussed in public forums, but all the brands do them. The most famous recent update was the caliber SW-200 from Sellita which infamously had problems with their winding mechanism that was resolved by changing the tooth profile and which requires replacing several components to keep them from breaking.

Until Oris comes up with an update for the components, turning the crown backward releases the tension and positions the teeth in a way that they can separate without forcing rotation.

Like the power-reserve concern, I wouldn’t let this discourage you from owning a watch with the caliber 400. This doesn’t cause anything to break or wear-out. It doesn’t affect the timekeeping of the watch. Once you get in the habit of turning the crown slightly backward this problem won’t even bother you at all.

Fig 8 - Illustration of the Caliber 400 escapement
Fig 8 – Illustration of the Caliber 400 escapement

As a watchmaker, the most exciting thing about this new watch is the escapement design, it caught me by surprise and I love what they have done. Oris claims to have designed an “entirely new escapement” and they did. Yes, it is still a swiss lever escapement, but it has some new and innovative features I have never seen before.

At first glance, this is a Swiss lever escapement constructed in silicon. Both the escape wheel and the pallet are made from silicon. Silicon offers some great advantages in escapements, namely:

  1. Silicon has a low coefficient of friction making it possible to avoid the use of lubricants in the escapement. No lubricants mean the escapement will perform exactly the same on the first day of the service interval as it will on the last.
  2. Silicon is anti-magnetic.
  3. It can be manufactured to very precise tolerances

Since the first advantage is probably the most important I was very surprised to see lubrication on the escapement. I can’t say for certain why Oris decided to lubricate the silicon escapement. Perhaps they found it performs even better when lubricated and found that the degradation over time had no significant impact on the performance.

Oris caliber 400 escapement
Fig 9 – The escapement of the caliber 400 with lubrication poorly applied

Certainly, the escapement continues to be antimagnetic (a fact which they advertise heavily), but it is in the third advantage where Oris has made some drastic changes.

In a traditional Swiss lever escapement, the pallet has two ruby stones which are adjustable. The only reason they are adjustable is that it would be nearly impossible (or at least incredibly

expensive) to machine the escapement components using traditional methods with enough precision to eliminate the need for adjustments. With silicon components, however, you can achieve amazing precision very inexpensively. Think about it: every year the computer industry manufactures billions of silicon chips each with millions of capacitors precisely etched onto the surface with a precision that rivals anything required in a mechanical device. Using photo-etching two-dimensional components like the escape wheel and pallet can be inexpensively and precisely produced. Precision being the keyword. In addition to the adjustable pallet stones, the traditional escapement has either banking pins or banking surfaces which limit the motion of the pallet. This new escapement from Oris does not have any traditional banking surfaces. Without the escape wheel in the watch, the pallet can swing freely side to side, well beyond the normal travel of a pallet in a watch. This is because the banking is built into the pallet itself. Instead of an oversized locking face, they have designed a precise locking notch in the pallet. The tooth bottoms out in this notch limiting the travel of the pallet. This is the first time I have seen this feature in an escapement and I don’t even know what we should call it. It fills the role of both the locking face and the banking surface.

Oris caliber 400 escapement
Fig 10 – The notch for locking and banking
Oris caliber 400 escapement
Fig 11 – The escapement showing the tooth locked in the notch of the exit stone

I will be curious to see how these escapements hold up over time. The banking action is the most forceful of all the escapement actions and normally that force is exerted away from any of the critical areas of the escapement, but in this design, the force is absorbed by the escape wheel teeth. Will they hold up? Only time will tell.

Overall, it is exciting to see this type of innovation in a brand’s initial caliber and I think the caliber 400 will withstand the test of time. It seems to be designed with modularity in mind. We have already seen caliber 401 with sub-seconds and I expect we will see more complications added to this watch as well. The small issues mentioned above wouldn’t be enough to keep me from adding a caliber 400 to my collection. Perhaps the biggest negative is their decision to use the caliber 400 in the Aquis Date instead of designing a brand new, unique watch for its release.

Jordan P. Ficklin
Posted by:Jordan P. Ficklin

Jordan P. Ficklin, CW21 is a certified watchmaker of the 21st century. He graduated from the Lititz Watch Technicum with a WOSTEP diploma in 2006. He is a co-owner of the Cincinnati Watch Co, designing and assembling watches in Cincinnati, Ohio, and the owner of Cincinnati Watch Repair, an independent watch service center meeting the needs of the microbrand and collector communities.