New Corum Golden Bridge Automatic For 2021: Linear Winding Never Looked So Good
Of all the watches extoling the virtues of the mechanical movement, no other piece does it as simply, cleanly, or in as straightforward a manner as the Corum Golden Bridge.
Invented in 1977 by independent watchmaker Vincent Calabrese, and first publicly available from Corum in 1980, the Golden Bridge displays like no other watch the beauty of the movement’s mechanics. And at a time when the Swiss watch industry found itself in the throes of the quartz crisis in the 1970s and early 1980s, this could not have been more important.
Strengthening transparency: Corum Caliber CO 113
The story of this new edition of the Golden Bridge Automatic starts several decades back with Corum’s second owner, Severin Wunderman, who looked to re-launch the Golden Bridge in time for Corum’s 50-year celebration in 2005.
Wunderman undertook an amazingly large project: to modify the classic Golden Bridge movement as designed by Calabrese and handmade by Corum’s watchmakers to make it more reliable for the modern era while maintaining the horological work of art’s integrity.
Corum’s delicate Caliber 13 became Corum’s sturdier Caliber CO 113 in time for the 50-year celebration thanks to a collaboration with Vaucher Manufacture. While the original version had an excellent, successful design, it had a few technical problems that made it somewhat unreliable and did not allow adding extra elements such as a tourbillon or automatic winding.
Corum’s biggest goal in this undertaking, though, was to modernize and reinforce the movement. Perhaps the biggest visible change was to move the winding stem from the back of the watch to the 6 o’clock position, which made winding easier.
Adding pillars to the movement also improved shock resistance while maintaining the integrity of its sandwich-style construction. Also, the frequency of the movement was upped from 3 Hz to 4 Hz, ensuring more precision (though, truthfully, when a watch looks this good, who needs to worry about that?).
The reinforced movement also made new mechanical iterations possible, the first of which arrived in 2009: the Ti-Bridge, which saw parts of the Golden Bridge crafted in titanium (including bridges and case) and the movement turned on its side.
In 2010, Vaucher’s engineers were finally able to add a largely silicon-manufactured tourbillon housed in what Corum claimed at the time was the world’s smallest tourbillon cage, coming in at 8.5 mm in diameter, resulting in a limited edition of 33 pieces of Caliber CO 213. Beating at the unusual frequency of 19,200 vph, its plate and bridges were crafted in hand-engraved 18-karat gold.
And, back to the subject today, in 2011 an automatic version of the Golden Bridge arrived, which this year celebrates its tenth anniversary.
2011 Corum Golden Bridge Automatic
Corum’s introduction of an automatic version of its famed baguette-shaped movement was a technical breakthrough and also an aesthetic one: adding automatic winding to the single-bridge construction of this bare-bones movement without destroying the famous aesthetic was nothing short of miraculous.
And more than a decade ago, and four years in the making, this advancement was partly possible because the La Chaux-de-Fonds-based brand had taken over creative watchmaker Laurent Besse and the remains of his company, Les Artisans Horlogers (who might be familiar to some through his work with MB&F on the HM1 and HM4). Besse is now an independent, behind-the-scenes watchmaker.
The challenge consisted in keeping the linear essence of the pared-down movement while adding a self-winding mechanism. Retaining the movement’s pure design, the unique solution was to invent a linear winding system.
This, however, brought three main challenges with it: winding capacity, the oscillating weight’s mass and, naturally, friction. Corum tried ten different material combinations before settling on cupro-beryllium and steel with a nickel-polytetra-fluoroethylene coating comparable to Teflon.
Beating at 4 Hz and endowed with a 40-hour power reserve, Caliber CO 313 was developed in conjunction with La Joux-Perret. One of the very rare movements to wind by linear oscillating weight, its inertia issues were solved by utilizing the dense precious metal platinum.
The four-gram oscillating weight moves along steel rails coated with the above-mentioned Teflon cocktail for one centimeter before its motion is slowed down by a system of gaskets that sends it back in the other direction.
The contact zones between the weight and the rails are made of beryllium copper. Energy generated is transmitted via a rack secured to the oscillating weight that is constantly engaged with a reverser system to offer unidirectional winding.
Equipped with ceramic ball bearings, the automatic winding of Caliber CO 313 requires no lubrication.
The 2021 Corum Golden Bridge Automatic
The 10-year-anniversary version of the Golden Bridge Automatic sees some aesthetic changes made to its avant-garde case, and in particular the iconic sapphire crystal.
Instead of the four sapphire crystal panels that Corum has used in the modern era of its cases, the Golden Bridge Automatic now features just two crystals: one enormous panoramic example covering the front and sides and one on the back revealing the motion of the automatic winding.
This allows for a 360-degree view of the gorgeous movement inside the case but was relatively tricky to complete due to the technical finesse required to obtain and retain a water resistance of 30 meters.
The sapphire crystal forming the back of the watch is smoky for a slightly mystical look (and to better conceal arm hair, which some people prefer not to see behind a watch).
The four new variations are housed in cases with crowns still placed at 6 o’clock to ensure the same technical reliability and pleasant winding experience. The case comes in polished Grade 5 titanium with black DLC treatment, a two-tone variation featuring the blackened Grade 5 titanium and 18-karat red gold, and two diamond-set variations. All four of these versions are limited editions.
The “dial” has also undergone a redesign, now utilizing a freshly arranged floating harness system for the hand-applied indexes. These are not attached to a dial as in previous Golden Bridges so that nothing impedes the full view of the movement. These indexes are attached to an unobtrusive frame secured to the movement base.
There is one other element about this watch worth highlighting: its very competitive price. Boon Soon Chong, global sales and marketing director for Corum, explains that this was a conscious decision made to, “Create buzz and reward clients, partners, and supporters of the brand.” Bravo!
While the Golden Bridge’s future keeps shifting shape ever so slightly, one thing remains constant: this diaphanous watch’s amazing ability to continue showcasing the watchmaker’s art as its original architects intended.
Elizabeth Doerr is the author of Bridging Art and Mechanics: The Unabridged Story of Corum’s Golden Bridge.
For more information, please visit www.corum-watches.com/collections/golden-bridge.
Quick Facts Corum Golden Bridge Automatic 2021
Case: 37.2 x 51.8 x 13.7 mm, titanium with black DLC treatment; two-tone 18-karat red gold with titanium with black DLC treatment; red gold and blackened titanium set with 72 diamonds (0.97 ct); blackened titanium and white gold set with 72 diamonds (0.97 ct)
Movement: automatic Caliber CO 313, baguette-shaped, 194 components in one line, 40-hour power reserve, variable inertia balance, 18-karat gold bridges, platinum linear oscillating weight, 4 Hz/28,800 vph frequency
Functions: hours, minutes
Limitation: 50 pieces (black titanium); 150 pieces (red gold/titanium with black DLC treatment); 100 pieces (red gold/titanium with black DLC treatment set with diamonds); 25 pieces (white gold/titanium with black DLC treatment set with diamonds)
Price: $29,000 (black titanium); $39,000 (red gold/titanium with black DLC treatment); $36,500 (red gold/titanium with black DLC treatment set with diamonds); $41,900 (white gold/titanium with black DLC treatment set with diamonds)