Armin Strom - Gravity Equal Force Only Watch 2023

For the 10th edition of the biennial Only Watch charity auction (Geneva, 5 Nov 2023), Armin Strom created the Gravity Equal Force Only Watch 2023.

For the 10th edition of the biennial Only Watch charity auction (Geneva, 5 November 2023), Armin Strom has created a unique edition of its successful Gravity Equal Force, the world’s first automatic watch with a constant force transmission.

The Gravity Equal Force Only Watch 2023 incorporates the promotional colors of the 2023 Only Watch event, with relevant details including a transparent green sapphire dial, a red logo, and blue stitching on the included custom strap. 

The one-of-a-kind timepiece offers an extraordinary view of the exquisitely finished manufacture movement, which features superior chronometric performance and exceptional hand-finishing, with a contemporary expression made in-house by Armin Strom’s master artisans.

For Armin Strom’s master watchmaker and co-founder Claude Greisler, the green yet transparent dial of the Gravity Equal Force Only Watch 2023 makes perfect sense. “Green is the colour of hope. And hope is important when it comes to this terrible disease for children,” he says, hoping the donated watch will bring a good contribution to Only Watch, the organisation which since 2005 has raised nearly CHF 100 million to accelerate the research on Duchenne muscular dystrophy.

The green off-centre sapphire dial shares the dial-face with Armin Strom’s signature tri-bridge design. This holds the microrotor, the winding mechanism and the patent pending Equal Force Barrel, an innovation that provides consistent power from the mainspring to the balance wheel, thus always ensuring flawless and constant precision during the power reserve.

This is achieved by using a Maltese cross inside the barrel to control the mainspring and stop it from fully unwinding. This cross is also declutched when the rotor has given the mainspring its optimum tension – a world first. By cutting the top and the bottom parts of the power reserve, a constant force is delivered with an extremely secure, stable and precise amplitude and isochronism throughout the entire cycle.

Technical excellence is paired to state-of-the art finishes. Crafted from stainless steel and featuring distinctive details like the angular lugs, the large crown and the small lip at 6 o'clock, the case measures 41 mm x 12.65 mm and is finished with an alternation of satin-brushed and polished surfaces. 

Through the sapphire crystal case back, it is possible to appreciate the superior finishes of the 202-component ASB19 calibre, whose balance wheel with 4 regulating screws beats steadily at the frequency of 3.5 Hz (25,200 vibrations per hour).

In line with Haute Horlogerie standards, decorations include polished bevels, black polishing, polished sinks, perlage and various grainings. 

Coated with dark grey ruthenium, the three bridges are fixed with mirror-polished screws on the black movement plate, which is hand-guillochéd by Kari Voutilainen’s atelier – the only part decorated by an outside friend of Armin Strom.

“Armin Strom is all about innovation connected with the science of movements,” says Serge Michel, founder of Armin Strom, who fully supports the mission of Only Watch founder Luc Pettavino. “When Luc asked us if we wanted to create a watch for him, we said: ‘Definitely, we are in.’ In 2023, we are donating a unique timepiece for the fifth time, and I salute that the auction is open to the whole watch industry, thus uniting the community for something good. With the Armin Strom Gravity Equal Force Only Watch 2023, we are not only supporting an important cause, but have also created something wonderful for passionate collectors desiring something unique.”

The Only Watch estimate for this model is CHF 25,000 - 35,000. arminstrom.com