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Calibre 860: a new expression of the chronograph
The Reverso Tribute Chronograph is powered by Jaeger-LeCoultre Calibre 860, which revisited the ground-breaking Reverso Chronograph Retrograde of 1996. Testament to the inventiveness and technical prowess of La Grande Maison, it was one of six special Reversos developed within just ten years, each designed around an entirely new expression of the great classical watchmaking complications. Its movement, Calibre 829, was not only the first rectangular shaped chronograph movement in a rectangular case of Jaeger-LeCoultre, but also the first manually wound integrated chronograph to be developed in the post-quartz era at Jaeger-LeCoultre. Like all Jaeger-LeCoultre movements, it was designed, produced, assembled and decorated at the Manufacture.
Calibre 860 is a fully integrated hand-wound chronograph movement with start/stop and reset pushers, a retrograde 30-minute counter, central seconds, and a second indication of time. In compliance with the Manufacture’s approach to product integrity, whereby a movement should be shaped according to the case that houses it, the calibre had to be rectangular. The result is a beautifully balanced and distinctive dial layout, with a large chronograph seconds display in the upper part of the dial, and the retrograde 30-minute indicator on an arc at the base of the dial.
Beating at 28,800 vibrations per hour, Calibre 860 incorporates a column wheel chronograph with a horizontal clutch, which was chosen over the more familiar vertical clutch to reduce the overall thickness of the movement. To display hours and minutes on both front and reverse dials, the movement powers two sets of hands that must move in opposite directions to indicate the time in correct clockwise fashion on both faces of the watch. Calibre 860 offers 52 hours of power reserve, allowing the high energy requirement of a retrograde chronograph to be combined with two time indications. Despite this complexity and no fewer than 300 components, Calibre 860 respects Jaeger-LeCoultre’s philosophy of elegance, fitting into a case of 11.14 mm of thickness.
