When the Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar was presented at the SIHH 2019 I was quite impressed by it, but unfortunately I didn’t get to spend much time with it back then. Later that year, I got to peruse the watch a second time and it continued to grow on me. Then, recently, I ran into a collector who was wearing one and I thought I should talk more about it and resurrect some of the content about this watch from our archives.

The Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar is a true feat of horology and one of the most underrated and under appreciated watches out there. Considering that this is a very good looking timepiece, I still don’t understand why this watch didn’t gain more popularity in the last couple of years.

Some might say that maybe the price tag is too steep while others simply just don’t care to understand how this watch works and why is worth talking about it. Well, simply because I think is a badass watch and one exceptional piece of horology, I am going to discuss everything I know about it, hoping that I get to see more of these watches out there.

The Traditionnelle Twin Beat Perpetual Calendar is inspired by the seasonal system from the Japanese Edo Period which divided day and night into six segments —of which the length varied from day to night and from one season to another—, the clocks from this period were equipped with a single or double foliot balance enabling automatic changes in their operating speed.

And just like those clocks, the Traditionnelle Twin Beat Perpetual Calendar beats at a high frequency when worn and on demand, it can be slowed down by pressing a pusher in order to guarantee an extended outstanding power reserve of at least 65 days when the watch is not been worn. An incredible power reserve never achieved before by any other wristwatch.

And right here right now, this watch is already in the money and that’s without even taking into consideration that this watch is a perpetual calendar and a very sexy one, if you ask me.

The Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar features a very generous 42 mm case in platinum and a partially open-worked dial with a sapphire disc on the lower half. Extremely thin and blending modern and traditional watch design cues, the Traditionnelle Twin Beat Perpetual Calendar utilizes a patent-pending mechanical system that allows instantaneous switching between Active mode where one balance wheel beats at a frequency of 36,000 vph —5Hz— or Standby mode where a second balance wheel beats at less than a quarter of the frequency during active mode at only 8,640 vph —1.2Hz. The modes get switched by pressing a pusher at 8 o’clock and the indicator on the dial couldn’t be easier to read.

Now, what I love about this complication is that the watch will continue to run on standby mode when not being worn and when it comes to a perpetual calendar there’s nothing better than not having to go through the hassle of setting the calendar every time that the watch has ran out of power reserve and is not been worn for days, weeks or months.

Then comes the outstanding power reserve of this watch. Via a color coded power reserve indicator at 12 o’clock, the power reserve for either frequency mode —Active at 5 Hz or Standby at 1.2 Hz— is show in black and red respectively.

While the Vacheron Constantin Twin Beat can provide a power reserve of only 4 days while beating at 5Hz, it can deliver an impressive 65-day power reserve while beating at 1.2Hz on standby mode. Both the Active and Standby balances are driven by the same mainspring barrel, which is the most efficient way of distributing energy and the only way to have a single power reserve indication.

Now, let me talk about the perpetual calendar indications that are positioned at the bottom of the dial and fitted with sapphire crystal discs that have been ink-filled for optimal readability. While the day of the week is not indicated by the Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar, the watch does indicate the month at 5 o’clock, the date at 7 o’clock and the leap year at 6 o’clock. The use of a sapphire crystal on the lower half of the dial allows for incredible views of the manual wound calibre 3610 QP underneath and that right there is the icing on the cake for me.

Lastly, the movement is a gem in itself. The manual wound in-house calibre 3610 QP is as good as it gets. Composed of 480 parts, this movement is an impressive feat of horology and micro-engineering on its own. The movement is fitted with two balance wheels and only one of them is allowed to oscillate at a time. Due to this, the hour and minute hands have to draw variable information from two gear trains for one reading of the time. This is accomplished by a gear differential that allows the hands to read more than one input source of timekeeping data. A second differential is mounted on the barrel for the dual purpose of winding the mainspring and also reducing the mainspring torque as it is directed towards the Standby mode balance equipped with a very delicate hairspring that was especially created for the slow-beat balance. Two final differentials translate the power reserve into the subdial that indicates the remaining mainspring wind.

The smaller balance wheel beats at a frequency of 36,000 vph, while the bigger balance wheel beats at a frequency of 8,640 vph. The movement plates and bridges are decorated with Côtes de Genève and then NAC treated giving the watch a more modern look when turning the watch over.

And even if after reading all that I just wrote, you still think that you rather spend the same amount of money —$200K USD— on a Patek Philippe ref. 5980/1R or on a black ceramic AP Royal Oak Perpetual, then all I can say is that you are out of your mind. For the money, it really doesn’t get any better. Vacheron Constantin proving once again their prowess as the oldest watch manufacture in the world.

Sticker Price $199,000 USD. For more info on Vacheron Constantin click here.