Roger Dubuis Chronograph with Lemania 2320: A Collector's Perspective

Key Points from the Discussion

• The Roger Dubuis RD 56 35 caliber is a heavily modified Lemania 2320, a base movement also utilized by prestigious brands like Patek Philippe and Vacheron Constantin. This highlights the high horological pedigree of early Roger Dubuis pieces.
• The Lemania 2310 (Patek's CH27) is considered one of the most important manual-winding chronograph movements due to its precision, reliability, and durability, famously passing NASA's stringent tests (Omega 321). It served as a base for many top chronographs from Breguet, Longines, Omega, Patek, and Vacheron Constantin, as well as independent makers like Roger Dubuis.
• Roger Dubuis designed specific modules to attach to the Lemania 2310 base caliber. The '49' in the movement stamp indicates it was the 49th movement produced by the manufacturer overall, not necessarily the 49th in a limited series, as Roger Dubuis did not use movements in chronological order.
• Each reference of these early Roger Dubuis pieces was produced in a maximum of 28 examples, with some series even smaller (19 to 28 pieces), underscoring their rarity.
• The RD 5632 caliber is specifically for perpetual calendar chronographs with moon phase, while the author's watch features a day-date chronograph with moon phase. The differences in complications would be visible under the dial and through case correctors for setting months and leap years.
• Breguet also utilized the Lemania 2310 base in their classic range chronographs, designated as Calibre 533.3, further illustrating the movement's widespread adoption among high-end brands.
• Minerva, now part of Montblanc, continues to produce high-quality chronograph parts in its original and new facilities, using upgraded CNC machines for calibers like the 13.21, evolving from the handmade 13.20 plans.