Les Cabinotiers is Vacheron Constantin’s programme dedicated to one-off and special-order watches. The latest to emerge from the workshop is the Les Cabinotiers Temporis Duo Grand Complication Openface, a large, complicated watch with an intricate calibre and an unusually modern, clear sapphire dial. The look is more contemporary than usual for a Les Cabinotiers grand complication, thanks to both the sapphire dial with its off-centre displays and a monochromatic grey finish on the movement.

An evolution (and stylistic upgrade) of the solid-dial Les Cabinotiers Minute Repeater Tourbillon Split-Seconds from 2022, the Temporis is underpinned by a base movement that features a minute repeater and tourbillon; on top sits a traditionally constructed split-seconds chronograph mechanism that is paired with the calibre in an unconventional manner.

The layers inside the cal. 2757 S of the Temporis

Initial thoughts

Twenty twenty-five has been good for Vacheron Constantin in terms of complicated watches – the brand started the year with the Solaria, the most complicated wristwatch ever made, and has followed up with the Temporis. In comparison to the Solaria with 41 functions and a price tag in the mid-millions, the Temporis is simple and affordable, but still impressive. Though it is largely identical in terms of the movement to the 2022 model with a solid dial, the Temporis offers a lot more visually with its open dial.

Though the look is modern – compare this to the baroque Bacchus – the mechanical approach is traditional. The construction of the movement is traditional, as is the decoration. While I am certain the movement execution is high quality, the grey finish lacks contrasts and arguably doesn’t do justice to the quality of finishing.

Although the chronograph on the front, instead of the back, is less traditional, this approach makes sense given the sapphire dial that reveals all of the details of the split-seconds chronograph. The split-seconds is classical in style, which gives the wearer even more to admire. And the construction is also clever, since the chronograph needs to be driven by the tourbillon.

As is usually the case for such watches, the Temporis is big, 45 mm wide and thick. Even though wearability is not ideal, that’s not necessarily a bad thing – such watches usually need to feel substantial enough for the level of complexity and price. In fact, I am certain the typical owner of such a watch would rather have it 45 mm than 37 mm.

Open-faced and complicated

“Openface” has been a recurring theme with Vacheron Constantin’s complications recently, but the Temporis deserves a see-through dial more than most. The wide sapphire dial features a trio of sub-dials arranged in an asymmetric manner: time at nine o’clock, elapsed minutes at two, and the constant seconds of the tourbillon cage at six.

The clear sapphire dial is actually two tone, each of the registers has a frosted sapphire chapter ring carrying the respective scales. The chapter rings in turn are ringed in pink gold that’s been applied via metal vapour deposition to the underside of the sapphire dial.

The dial reveals most of the finely shaped split-seconds chronograph works. The mechanism is traditional in form, with twin column wheels and a split-seconds controlled by a pair of pincers.

But because of the layered construction of the cal. 2757 S inside, the chronograph has a novel lateral clutch mechanism that engages with the tourbillon; in other words, when the chronograph is activated, it engages with the driving wheel of the tourbillon.

The layered construction also explains the thickness of the 18k pink gold case, which is 16.4 mm high. The case adopts the Traditionnelle style, with subtle Maltese cross elements integrated into the lugs.

The chronograph layer separated from the base movement

From the back, the cal. 2757 S is more familiar. It’s actually based on the cal. 2755, a minute repeating movement with tourbillon that’s been in Vacheron Constantin’s portfolio for some two decades.

The cal. 2757 S seen from the dial (left), and back

The base movement features a minute repeater with a “silent” centrifugal governor. Both the governor and hammers are visible on the back, along with the gongs that circle the movement. Also on the back is the power reserve indicator.

While past movements in the cal. 2755 family all featured a tourbillon, the cal. 2757 S is notable to having a spherical hairspring in the tourbillon. This is an ideal complement for the split-seconds chronograph under the dial, since the additional height required for the spherical hairspring provides the volume for the chronograph and vice versa.

A variation of the cylindrical hairsprings historically found in marine chronometers, the spherical hairspring has been employed in past Les Cabinotiers models, most notably in the Armillary Tourbillon. Its purpose is to improve chronometry as the spherical shape results in more concentric “breathing”, which improves isochronism and reduces positional variation.

The tourbillon assembly

Though the layout of the cal. 2757 S is familiar, it’s been decorated in a more modern manner. The bridges are frosted but outlined by raised borders that are straight grained. The borders are matched with relief markings on the bridges; then the Poinçon de Genève emblem and Maltese cross are in relief.

Key facts and price

Vacheron Constantin Les Cabinotiers Temporis Duo Grand Complication Openface
Ref. 9750C/000R-215C

Diameter: 45 mm
Height: 16.4 mm
Material: 18k pink gold
Crystal: Sapphire
Water resistance: Not water resistant

Movement: Cal. 2757 S
Functions: Hours and minutes, split-seconds chronograph, minute repeater, tourbillon, and power reserve indicator
Winding: Manual-wind
Frequency: 18,000 beats per hour (2.5 Hz)
Power reserve: ~58 hours

Strap: Alligator with folding clasp

Limited edition: Unique piece
Availability: At Vacheron Constantin boutiques
Price: On request

For more information, visit vacheron-constantin.com.