Zenith reinterprets the fusee & chain constant force mechanism in a modernistic style in the new DEFY Fusee Tourbillon. Housing the new El Primero 4805 SK calibre, a manual-winding movement that follows the DEFY code of avant-garde movement architecture with an open three-dimensional impact, the DEFY Fusee Tourbillon is available in two distinct editions in Carbon and Platinum.
Upon a first glance, it’s immediately clear that the DEFY Fusee Tourbillon’s calibre is out of the ordinary. The spoke design of the bridges is amplified by their bicolor finish, where the top satin-finished surface is given a black treatment, while its polished sides are a lighter grey rhodium tone. The layout of the bridges offers a balanced layout of the various functions and complications. On the top half of the movement, one can admire the uniquely conceived fusee and chain constant force mechanism. The chain, which consists of 575 individually hand-assembled components, features a bold blued treatment: a first for a wristwatch fusee and chain system. On the opposite end at 6 o’clock, a tourbillon cage with an entirely new construction featuring an off-centered balance wheel makes a full rotation every 60 seconds. Like the chain, the tourbillon cage is embellished with a striking blue colour, reinforcing the visual effect of the DEFY Fusee Tourbillon’s unique moving parts. Positioned at the edge of the dial between 4 and 5 o’clock, a red-tipped hand indicates the power reserve, a handy feature when manually winding the DEFY Fusee Tourbillon with its 50-hour power reserve.
As a mechanical movement’s mainspring unwinds, the torque it delivers to the regulating organ drops, resulting in less efficient chronometric performance of the movement. A centuries-old solution to counter this and achieve constant force lies within the power source and its transmission. Known as the “fusee and chain” system, it features miniature chain is coiled around a conical “fusee” and attached to the mainspring barrel. As the mainspring unwinds, more of the chain wraps around the barrel, detaching itself from the wide conical base of the fusee. The greater turning movement provided by the fusee compensates the weakening mainspring pull, thus maintaining the torque and, consequently, the amplitude of the regulating organ constant throughout the duration of the mainspring’s autonomy.
While each version will appeal to a different kind of forward-thinking watch aficionado, one thing is certain: the DEFY Fusee Tourbillon solidifies Zenith’s position as a leader in building the future of watchmaking.
ZENITH DEFY FUSEE TOURBILLON
DEFY FUSEE TOURBILLON LIMITED EDITION 50
Reference: 10.9000.4805/78.R916
Full Carbon model: Case, crown and buckle head
Exclusive combination : Tourbillon Fusee-Chain Calibre
Chain made of 575 components
Manual winding El Primero Tourbillon with Fusée-Chain escapement
Constant force fusée-chain transmission connected to the barrel
MOVEMENT
Movement El Primero 4805 SK, Manual
Calibre 16½“` (Diameter: 37 mm)
Movement thickness: 5.9 mm
Components: 807
Exclusive bicolor signature on plates and bridges
Jewels: 34
Frequency: 36,000 VpH (5 Hz)
Power-reserve approx.: 50 hours
Finishes: Special oscillating weight with satined finishings
FUNCTIONS
Hours and minutes in the centre
Tourbillon:
– The carriage is positioned at 6 o’clock
– The carriage makes one turn per minute
Power-reserve indication between 4 and 5 o’clock
Fusée-chain transmission connected to the barrel
CASE, DIAL & HANDS
Diameter: 44 mm
Diameter opening: 36.5 mm
Thickness: 13.35 mm
Crystal: Domed sapphire crystal with anti-reflective treatment on both sides
Case-back: Transparent sapphire crystal
Material: Black carbon
Water-resistance: 10 ATM
Dial: Carbon Openworked
Hour-markers: Transferred
Hands: Black ruthenium-plated, faceted and coated with SuperLuminova SLN C1
STRAP & BUCKLE
Strap: Black rubber with black rubber “cordura effect”
Buckle: Titanium double folding clasp with black carbon head
DEFY FUSEE TOURBILLON LIMITED EDITION 10
Reference: 40.9000.4805/75.R582
Exclusive combination: Tourbillon Fusee-Chain Calibre
Chain made of 575 components
Manual winding El Primero Tourbillon with Fusée-Chain escapement
Constant force fusée-chain transmission connected to the barrel
MOVEMENT
Movement El Primero 4805 SK, Manual
Calibre 16½“` (Diameter: 37 mm)
Movement thickness: 5.9 mm
Components: 807
Exclusive bicolor signature on plates and bridges
Jewels: 34
Frequency: 36,000 VpH (5 Hz)
Power-reserve approx.: 50 hours
Finishes: Special oscillating weight with satined finishings
FUNCTIONS
Hours and minutes in the centre
Tourbillon:
– The carriage is positioned at 6 o’clock
– The carriage makes one turn per minute
Power-reserve indication between 4 and 5 o’clock
Fusée-chain transmission connected to the barrel
CASE, DIAL & HANDS
Diameter: 44 mm
Diameter opening: 36.5 mm
Thickness: 13.35 mm
Crystal: Domed sapphire crystal with anti-reflective treatment on both sides
Case-back: Transparent sapphire crystal
Material: Platinum 950
Water-resistance: 10 ATM
Dial: Openworked
Hour-markers: Transferred
Hands: Rhodium-plated, faceted and coated with SuperLuminova SLN C1
STRAPS & BUCKLES
Strap: Black rubber with black alligator leather coating
Buckle: Titanium & white gold double folding clasp
