The tourbillon was invented more than two centuries ago to improve rate results by equalizing the influence of gravity on the balance. The escapement and balance wheel rotate within a cage – in most tourbillons, including this one, at a rate of once per minute – to ensure that the force of gravity is distributed evenly onto the balance and escapement.
The mechanism was invented for use in pocketwatches, and does indeed improve precision when a watch is in a vertical position, as most pocketwatches are (or were) when being worn. In horizontal positions, though, where wristwatches spend most or at least much of their time, the tourbillon provides no benefit.
Hence we were very anxious to see how well this tourbillon movement, Cal. 2260, fared in all six positions on a timing machine. The extremely high power reserve, made possible by four paired barrels (the springs have a total length of 2.2 meters) presents a special challenge, since it’s virtually impossible to provide constant power over such a long period.
When testing a watch with a minute tourbillon on a timing machine, it’s important that each position be tested for at least one minute so the tourbillon can demonstrate its equalizing effect on the gravitational forces. We tested each position for five minutes, our usual testing period, to be sure the tourbillon had plenty of time to prove itself.
As we expected, the vertical positions were close together. A bit too much power is supplied to the balance in the horizontal positions, as shown by the high amplitudes. For 12 hours after winding, the most important interval for a manual-wind watch, the rate results were generally good. The greatest deviation between all the positions was five seconds per day and the average deviation was +2 seconds. Even after seven days, the Patrimony was still running accurately, with no more than a one-second difference between any of the vertical positions.
Only after 13 days did the power begin to decline and the difference between the positions begin to increase. The average gain was still only around two seconds per day, but it became apparent that the tourbillon mechanism requires a substantial amount of power. Throughout the 14 days, the difference in amplitude between the horizontal and vertical positions, about 60 degrees, was roughly twice that of a conventional watch. The Vacheron Constantin nonetheless achieved good rate results for most of the running period.
The watch meets the new standards for the Geneva Seal established in 2012. The old criteria addressed the quality of the movement’s finishing and materials and nothing more. Now the entire watch is included in the inspection. Rate results, the function of the operating elements, water resistance and whether the watch runs for its stated power reserve are all part of the examination.
Now, about the price. Nearly $300,000 is a big pile of money, even in the world of ultra-high-end watches this Vacheron inhabits. A long-power-reserve tourbillon can be had for less. But if you’re even contemplating buying this watch, you’re probably not bargain hunting.
Manufacturer: Vacheron Constantin, Chemin du Tourbillon 10, CH-1228 Plan-les-Ouates/Geneva, Switzerland
Reference number: 89000/000R-9655
Functions: Hour, minutes, seconds, power-reserve display, tourbillon
Movement: Vacheron Constantin Caliber 2260, manual-wind, 18,000 vph, 31 jewels, fine regulator with screw adjustment, four barrels, 14-day power reserve; diameter = 29.10 mm, height = 6.8 mm
Case: Rose gold, curved sapphire crystal, fully threaded caseback, sapphire window, water-resistant to 30 meters
Strap and Clasp: Alligator leather strap with rose-gold double folding clasp
Rate results (Deviations in seconds per 24 hours):
(Fully wound / after 12 hours / 7 days / 13 days)
Dial up: +3 / +5 / +6 / +14
Dial down: -1 / 0 / +2 / +11
Crown up: +1 / +2 / +2 / -5
Crown down: 0 / +2 / +1 / -1
Crown left: 0 / +1 / +1 / -3
Crown right: 0 / +2 / +2 / -4
Greatest deviation of rate: 4 / 5 / 5 / 19
Average deviation: +0.5 / +2 / +2.3 / +2
Strap and clasp (max. 10 points): The strap has a beautiful texture and is neatly hand sewn. Its edges are varnished. 9
Operation (5): Smoothly operating crown. As with most tourbillons, there is no hack mechanism. 4
Case (10): Superbly finished rose-gold case with sapphire caseback. 9
Design (15): The slightly asymmetrical dial with offset center and the polished case are elegant, unpretentious and timelessly beautiful. 14
Legibility (5): The hands contrast well with the dial and the power-reserve display is also easy to read. No luminous material was used. 4
Wearing comfort (10): Despite its size, the watch lies comfortably on the wrist. 9
Movement (20): Vacheron Constantin has refined the tourbillon with an extended power reserve and provided it with hand-applied decorative finishes. 19
Rate results (10): Low average deviation and little difference between the various positions. The tourbillon ensures a balance in the vertical positions. 8
Overall value (15): This watch has a very high price. Even in comparison with other tourbillons with long power reserves, the Vacheron Constantin remains at the upper end. 10
TOTAL: 86 POINTS