F.P. Journe Chronomètre Optimum Ref. CO

The F.P.Journe Chronomètre Optimum, reference CO, houses the manually wound Calibre 1510 in 18K rose gold, available in 40mm or 42mm cases of platinum or 18K 6N gold, with an overall height of 9.5mm. The movement brings together a remarkable concentration of horological engineering rarely combined in a single watch, two parallel mainspring barrels, a one second constant force remontoire at 11 o'clock, and the High-Performance Bi-axial Escapement (EBHP), an oil free direct impulse escapement with titanium arbor and wheels inspired by eighteenth century natural escapements. The result is a natural dead beat seconds function visible on the case back, where the seconds circle is screwed directly to the movement's bridges, framing the mechanism in 18K rose gold finished with circular graining, Geneva waves and polished, chamfered screw heads.

On the dial, off centre hours and minutes sit at 3 o'clock, a small seconds counter at 9 o'clock, and the power reserve indicator at 6 o'clock, all set against white gold or 5N gold dials with whitened guilloché silver detailing and blued steel hands. The calibre runs at 21,600 vibrations per hour with a power reserve of 70±2 hours, the first 45 hours of which benefit from constant amplitude thanks to the remontoire mechanism. Originally designed by François-Paul Journe in 2001, the Chronomètre Optimum represents the culmination of his research into isochronism and friction reduction, marking the first watch to combine the constant force remontoire with a natural dead beat second in a single calibre, and remains one of the most technically accomplished references within the Classique collection.