The fusée and chain mechanism has held its place in horological history since the 15th century as the equalizer which evened out the pull of the mainspring. Its purpose" To improve the precision of timekeeping throughout the entirety of a watch’s power reserve. Zenith has long been a well-regarded name when it comes to implementing the constant force of the fusée and chain system in its timepieces. We are, of course, talking about the Zenith Academy Georges Favre-Jacot watch. Named after the founder of the Le Locle-based brand, the timepiece was recreated in 2016 to commemorate 150 years since Zenith’s inception.

Fast forward to 2019 and the new Defy Fusée Tourbillon has been introduced as an avant-garde attempt by the brand to modernize the movement architecture of the ?constant force? mechanism by combining it with a tourbillon. Available in two distinct case materials in carbon and platinum ? both sized at 44 mm ? the latest addition to the Defy collection features the manual-winding El Primero 4805 SK caliber.
The caliber features an integrated fusée and chain mechanism visible in the upper portion of the dial. The chain consists of 575 individually hand-assembled components in a very bold blue hue. At the 6 o’clock position, a new tourbillon cage design for Zenith can be found with an off-centered balance wheel that makes a full rotation every 60 seconds. The tourbillon cage matches the vibrant color of the fusée and chain. To the right of...