The Caliber 11 is a 17-jewel modular chronograph measuring 31mm x 7.7mm. This modular architecture implies first a base movement, a micro-rotor automatic caliber made by Büren, in charge of the timekeeping part. Beating at 19,800 vibrations per hour, it boasted 42 hours of power reserve. Manufactured by Dépraz, the lever chronograph module is assembled on the backside of the base movement. This movement has a bi-compax display, with a 30-minute counter at 3 o’clock and a 12-hour counter at 9 o’clock – no running seconds sub-dial. The date is indicated at 6 o’clock. The unusual crown position, at 9 o’clock at the opposite of the chronograph pushers, is a signature feature of the movement.
Like most movements, the Calibre 11 has been optimized several times over its lifetime. As early as 1969, a barrel spring providing less torque is used. The date jump mechanism is adapted. The sliding pinion is changed and made in steel...
In 1971, a variant running at 21,600 vibrations per hour and named Calibre 12 is introduced. It becomes the main product of the calibre family. It uses a stronger barrel spring. The gear train and balance wheel are adapted. The chronograph hammer is modified to improve shock-resistance.
