The Excalibur Bi-Retrograde Calendar by Roger Dubuis

This year, Roger Dubuis celebrates its 30th anniversary, and for the occasion, the company pays tribute to its co-founder’s favourite complication: the bi-retrograde display.

This function, previously featured in the Excalibur Grande Complication alongside a dozen other highly complex mechanisms, takes centre stage once again. The Maison has also introduced a less complicated, more classic edition to further honour the bi-retrograde display.

Also referred to as “the ecliptic counters” by the Maison a nod to their elliptical shape and distinctive role in indicating the months and date the design showcases a symmetrical dial layout. Enhanced by refined detailing, it pays homage to the Maison’s early creations from 1996.

Glossary

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Glossary
Remontoire

Remontoire

The word remontoire comes from the French word “remonter“, meaning “to wind”, and it is a secondary, smaller spring used to apply power to the balance and escapement mechanism of a timepiece. The remontoire itself is then periodically re-wound by the power from the mainspring. It serves to stabilize the drive force transmitted to the escapement and compensates for variations in the geartrain's friction. It ensures accuracy by managing the power distribution throughout the clock.

There are different types of remontoires, including gravity remontoires and spring remontoires. Gravity remontoires counteract fluctuations in force caused by the mainspring winding down, while spring remontoires utilize a spring as their power source.

Remontoires are designed to rewind periodically, ensuring long-term accuracy by averaging out rate variations. The concept of a remontoire is not new, with historical roots dating back to Swiss clockmaker Jost Burgi in 1595, who invented the gravity remontoire, and English clockmaker John Harrison in 1739, who created the spring remontoire.