A tourbillon that beats at 72,000 vibrations per hour! Breguet's "Experimental 1" is a mechanical linear motor car!

Breguet has been thrilling watch enthusiasts throughout 2025. Who would have expected that the company celebrating its 250th anniversary would release such a diverse range of new products? The pinnacle of this success is the Breguet Experimental 1, released on December 1st. The tourbillon, which beats at an unprecedented 72,000 vibrations per hour, is made possible by a magnetic escapement.

Breguet's 250th anniversary finale is marked by the "Experimental 1"

　Breguet, celebrating its 250th anniversary in 2025, has released seven commemorative models, starting with the "Classique Subscription" in the spring and continuing with the "Classique 7225" and "Classique 7235" in November. The final model is the "Experimental 1," which thoroughly pursues precision. As the name "Experimental" suggests, this is a commercially available experimental model. Breguet CEO Gregory Kisling said, "Abraham-Louis Breguet's ambitious watches are often called 'Experimental,' so we adopted that name for this watch. This is the first one."

What is the escapement that enables the ultra-high-beat tourbillon to beat 72,000 vibrations per hour?

　The main feature of the Experimental 1 is that it combines an ultra-high frequency of 72,000 vph with a tourbillon. Large and heavy tourbillons are typically run at a low beat. However, Breguet has created an unprecedented tourbillon by using a new magnetic constant-force escapement.

　As far as I know, almost all mechanical watches from the late 17th century onward have had the same mechanism (with the exception of electromagnetic balance wheels and Spring Drive). The rotary motion of the mainspring is converted to left-right motion by an escapement consisting of an escape wheel and pallet, which then oscillates the balance wheel. The ultimate form of this mechanism is the club-tooth lever escapement (also known as the Swiss lever escapement), which is used in almost all mechanical watches today. This was an ideal escapement—it was shock-resistant, highly manufacturable, and automatically started working once the mainspring was wound. However, improving its performance was difficult. This is because, like previous escapements, the rotary motion was converted to left-right motion by the physical contact between the escape wheel and pallet, which created a lot of resistance. The current silicon escapement is, roughly speaking, a kind of "symptomatic treatment" that reduces resistance by making the material itself lighter.

　In contrast, Breguet's magnetic constant-force escapement separates the actions of "advancing" and "stopping," which are the functions of all escapements, into two. Furthermore, the advancing action is performed by magnetic force, not physical contact. To put it in perspective, it's like a linear motor car that moves by the repulsive force of magnets. The stopping action relies on physical contact, but at least the advancing action is contactless, so the resistance of the escapement should be greatly reduced. Reducing resistance makes it possible to significantly increase the frequency of the balance. This is why Breguet was able to create a tourbillon that operates at 72,000 vibrations per hour.

　Incidentally, the company adopted a magnetic pivot, which supports the balance wheel axis (balance) with a magnet, in the Classique Chronométrie 7727, unveiled in 2012, and its successor, the 2025 Classique 7225. This prevents the balance wheel from shifting and losing performance by supporting it with magnetic force. Indeed, if the balance wheel is firmly supported, it will not shift due to the effects of gravity. Furthermore, by suspending the balance wheel with magnetic force, it eliminates the friction that traditionally occurs when the balance wheel comes into contact with the hole jewel. This is why the company calls it the "tourbillon of the 21st century." Its vibration frequency is the same as the Experimental 1, at 72,000 vph. Its accuracy, too, is within ±1 second in the latest Classique 7225, far exceeding the standards of mechanical watches. However, it would have been difficult to match this with Breguet's specialty, the tourbillon.

　A tourbillon is a mechanism that encloses the heart of a watch—the escapement and balance—in a large frame (carriage) and rotates it once every minute (in the past, it was also four or seven minutes). Theoretically, the vertical effects of gravity are canceled out by rotating the heart of the watch. In contrast, a magnetic pivot fixes and cancels the effects. While incorporating a tourbillon would likely improve performance, it's difficult to support a heavy carriage with a small magnet (this is likely one of the reasons why the Classique 7727 and Classique 7225 are ultra-high-frequency movements with small balances). Furthermore, adding magnets above and below the balance shaft detracts from the aesthetic appeal. By using magnetism in the escapement, Breguet has achieved both ultra-high frequency and high accuracy. Breguet has announced that the accuracy of the Experimental 1 is within ±1 second. Considering the ultra-high frequency of 72,000 vph, it's likely that the accuracy on the wrist will fall within the same range.

　The Breguet development team explains that the advantage of the magnetic constant-force escapement is that it allows the tourbillon, which has a large inertia, to rotate at a high frequency. Indeed, this escapement, which has almost no contact other than to stop the movement, can significantly reduce resistance.

　The escapement mechanism is quite unusual. Like a normal club-tooth lever escapement, the gear that meshes with the pallet has a concave or convex shape like an escape wheel. However, this only stops the pallet's movement from side to side. Unlike a normal escape wheel, it does not move forward. This is why Breguet gives it the rather blunt name of a "stop gear." In contrast, the movement that moves forward is performed by rings stacked above and below the stop gear, and the pallet that swings back and forth. Each of these parts has a magnetic force, and the pallet, which is sandwiched between the rings, moves in opposition to the magnetic force of the rings. This movement is similar to that of a linear motor car, which moves forward by repelling the magnetic force embedded in the track (guideway).

　The magnetic constant-force escapement advances due to the repulsive force of the magnets attached to the anchor and the ring that holds the stop gear. Because there is no physical contact, resistance is reduced and lubrication is unnecessary (although the stop wheel that stops the anchor is apparently coated with a special oil on its contact surface). In addition, because the magnetic force is constant, the energy transmitted to the balance wheel does not change at all. This is why it is a constant-force escapement that provides a constant force to the balance wheel. Moreover, because the escapement itself is constant-force, the force is supplied steadily as long as the escapement continues to operate. This is completely different from a typical constant-force escapement, which is canceled out when the force of the mainspring weakens. A Breguet official explained, "The constant-force works perfectly for three days."

The power of the magnetic constant-force escapement

　Its performance is overwhelming. As mentioned above, the daily accuracy is within ±1 second. Moreover, theoretically, performance remains unchanged even when the mainspring unwinds and loses its force. A Breguet insider boasts, "The balance wheel swings at a constant 260 degrees, with virtually no positional error." Furthermore, the mainspring itself, the watch's power source, is unique. "This model has a double barrel, but each barrel actually houses two mainsprings. The reason is that using a longer mainspring stabilizes torque output." Additionally, the barrel stem is narrower, a design favored by the Swatch Group, allowing for a longer mainspring. This explains why this high-frequency chronograph, beating at 72,000 vph, has a power reserve of approximately three days.

　Despite the built-in magnet, this model has a magnetic resistance of 600 gauss (approximately 48,000 A/m), which is about 10 times the resistance of normal magnetic fields. In theory, it could be even higher, but Kissling explains, "No one would wear this watch while going into an MRI, so this is sufficient." The high magnetic resistance is achieved by the non-magnetic material Nivagauss. This material, which gave Omega watches a magnetic resistance of 15,000 gauss, was used by Breguet in parts such as timepieces, greatly improving their magnetic resistance.

　Incidentally, reducing the proportion of iron in a material improves its anti-magnetic properties. On the other hand, it becomes softer and less durable. While the previous Nivagaus had durability issues (which is said to be the reason why Tudor and Rolex began making their timepieces out of ceramic), the new Nivagaus no longer poses any problems when used in movements that operate at 72,000 vph. "This material is widely used not only by Breguet but also by the Swatch Group," says Kisling.

　The same can be said for magnets. Previous magnets had an unstable center of magnetic flux, making them unproductive. This is likely why the magnetic pivot was shelved for a while. However, starting with this year's Classic 7225, the magnet-related issues have been resolved by adopting an entirely new magnet. "We have been working on this project for a long time. The project of a magnetic escapement has been around for a long time, and when I became president, I discovered this mechanism and began working on commercializing it. So it is quite mature. We have made many prototypes."

Pay attention to the movement finish and exterior.

　This model is new not only in its movement, but also in its finish and exterior. The movement's baseplate and bridges are made of Breguet gold, as with the 250th anniversary model. Furthermore, portions of the bridges are blued using a process called "ALD," rather than DLC, PVD, or CVD. Incidentally, PVD produces stable coloring but is limited in the colors available; DLC produces a stronger coating but similarly offers a limited range of colors; and CVD produces colors but is less stable (at least, it's difficult to produce vivid colors). In contrast, ALD produces a thinner, harder coating, can cover a larger area, and produces better coloring. Additionally, presumably due to its flexibility, Breguet also applied this treatment to the mainspring.

"ALD is a good treatment, but the film it creates is hard. Therefore, after the treatment, it is quite a hassle to peel off the film in order to chamfer the edges. It can be easily removed by cutting, but for models bearing the Breguet Seal, the chamfering is done by hand, which is quite a hassle" (Kisling). Incidentally, this treatment is also used on the tourbillon carriage bridge of the recently announced "Classique Grande Sonnerie Métiers d'Art 1905." The color is so vibrant and the film is so thin that I mistook it for a blueprint.

　The greatest strength of this model is its excellent wearability. While the case size is by no means small, at 43.5mm in diameter and 13.3mm thick, the shortened lugs and soft rubber strap make it feel quite comfortable on the wrist. Moreover, the low center of gravity means it should be comfortable to wear for long periods of time. Despite its high-beat tourbillon, clocking in at 72,000 vibrations per hour, it feels comfortable to wear and is also water-resistant to 10 bar. Additionally, thanks to the interchangeable straps, it should be able to be worn in any situation (although unfortunately, there are still only a limited number of strap options available).

　The price is said to be 32 Swiss francs, or 5348 million yen (tax included) in Japanese yen. It's certainly not cheap, but when you consider that it's an experimental model with a tourbillon that vibrates at 20 vibrations per second, the movement is Breguet gold, and it's limited to just 75 pieces, it actually seems quite reasonable. Kissling says that "the experimental collection will continue into the future." With this model, Breguet, which is finally approaching the finale of its 250th anniversary, has kicked off the next year. Hats off to its overwhelming power.