Shopping Cart

Armin strom sets the tone in the realm of transparent mechanics with the Gravity Equal Force Ultimate Sapphire Purple

MAY 06 2024    |    Novelties

Armin Strom fuses masterful mechanics with a bold chromatic twist, unveiling its latest Ultimate Sapphire Edition. The iconic Gravity Equal Force now sports a striking purple guilloché-engraved mainplate by Kari Voutilainen. 

Armin Strom’s System 78 collection represents the independent manufacture’s purest expression of innovative haute horlogerie. Within it, the classical codes of watchmaking are revisited to bring about new functions and solutions, while also expressing the brand’s unique aesthetic sensibilities. With an emphasis on transparency, as well as highlighting kinetic elements, the Gravity Equal Force stands out as a technical tour-de-force with an instantly recognisable look – outstanding in form and function, finished by meticulous hand decoration. Now, with the new ‘Purple’ Ultimate Sapphire Edition, Armin Strom is doubling down on integrating vibrant chromatic hues with exceptional mechanics.

Let it reign: Gravity Equal Force Purple

At once regal and electric, the latest edition of the Gravity Equal Force features a colour Armin Strom has never used before. Its base plate boasts a guilloché engraved motif with a barley grain pattern, expertly handcrafted in the atelier of acclaimed independent watchmaker Kari Voutilainen using a traditional rose engine lathe. The striking purple colour is applied using a 3D PVD process, which reflects a wide spectrum of tones as it shifts with the light. Making this edition even more outstanding, the small off-centred dial is crafted from transparent sapphire crystal, which is reserved exclusively for the Gravity Equal Force’s Ultimate Sapphire Editions. The crowning glory is a light grey nubuck leather strap with purple stitching and keepers. The Gravity Equal Force Ultimate Sapphire Purple is limited to a run of 25 pieces per year.

 

Automatic: redefined

The Gravity Equal Force stands out as the first automatic watch endowed with an equal force transmission integrated directly in the mainspring barrel - a patented mechanism by Armin Strom. It provides consistent power transmission to the regulating organ, ensuring unwavering precision throughout the watch’s autonomy. The power reserve indicator forms part of the barrel, which is entirely visible from the dial side, opposite the micro-rotor with a unique click system featuring two springs for better winding efficiency.

Also this latest creation, part of Armin Strom’s perpetual quest for superior chronometric performance, was entirely developed, manufactured and decorated within the walls of the Bienne-based manufacturing site. Like all Armin Strom watches, the Gravity Equal Force Purple’s movement is assembled a first time to ensure it is in perfect working order and that it meets the brand’s exacting decorative standards, then taken apart and assembled a second time when it is ready to be cased in its final form. 

 

Putting the ‘haute’ in ‘horlogerie’

What separates a mere tool from a work of art is craftsmanship. Like a canvas for artistic expression, superlative hand-finishing applied by specialised watchmakers and seasoned artisans can be appreciated throughout the Gravity Equal Force and its many proudly exposed layers and components. Polished bevels (anglage) on the bridges, black polished screws, polished countersinks, perlage and various types of graining, be it straight or circular, as well as Geneva stripes on the three-quarter bridge visible through the case’s back.

One of the Gravity Equal Force’s most distinctive elements is the triplet of dark grey ruthenium-plated bridges that occupy the right-hand portion of the open display. Inspired by the finger-style bridges found in pocket watches, it takes up to an entire day for these bridges to be embellished by hand. First, the undersides are given a matt finish, after which the sides are given a straight-graining finish by carefully sliding them on an abrasive paper to produce continuous, shimmering fine lines. Then, the inner and outer chamfers of the bridges are bevelled with increasingly fine files and then finished with a flash polish using locally sourced gentian wood to remove even the finest lines. Finally, a straight-graining finish is applied to the top side for ultimate radiance.

Armin Strom : 15 years in the science of movement

In 2008, longtime friends and partners Serge Michel and Claude Greisler took the reins at Armin Strom and founded its very own manufacture in the watchmaking town of Biel in 2009. Just one year later, the duo presented their very first watch with a movement designed and manufactured in-house. Over the following years, Armin Strom would become a truly integrated and self-sufficient manufacture, creating 17 exclusive calibres and developing several world firsts in the domain of watchmaking. In 2016, it introduced the Mirrored Force Resonance, a game-changing resonating dual regulator developed for maximum chronometric precision with a captivating oscillation mechanism on the dial-side of the watch. In 2019, Armin Strom reinvented the automatic watch movement with the Gravity Equal Force, the first automatic watch to feature an equal force transmission mechanism within the barrel that had previously been found only in pocket watches. Today, Armin Strom stands out as a leading force of creative, independent watchmaking, with its own distinct design language and exceptional attention to detail highlighted by hand-finishing all its creations. 2024 promises to be a year full of surprises, and the best is yet to come…

 

Gravity Equal Force Ultimate Sapphire Purple

Technical specifications

                   

Indications     Hours, minutes, seconds, power reserve indicator
Movement     Armin Strom manufacture Caliber ASB19
      Automatic winding with micro rotor, Geneva-drive equal force barrel, offset display with subdial seconds
Main plate   purple PVD plate with guilloché pattern by Kari Voutilainen
Regulating system   Balance wheel with 4 regulating screws
Power reserve   Geneva stop-work limited to 72 hours
Dimensions   35.52 mm x 11.67 mm
Frequency   3,5 Hz (25,200 vph)
Finishing   Hand-finishing to the highest quality level
Jewels   28
Number of components   202
Case   stainless steel
    Sapphire crystal and case back with anti-reflective treatment
Diameter   41 mm
Height   12.65 mm
Water resistance   3ATM
Lug-to-Lug   48.09 mm
     

Dial

 

Grey toned off-center sapphire dial with subdial

Hands  

Faceted polished hands and Super-LumiNova® filling

Strap   Delivered with a grey nubuck leather strap with purple stitching and keepers
Width lugs/buckle   20/18 mm
Buckle   Pin buckle or folding clasp available in stainless
Reference   ST24-GEF.SA.AC.M.A7.FC
Limited production   25 pieces per year

 

 

                                           

                                            

 


Related Articles

JULY 15 2026    |    Novelties

A New Pulse of Colour: Armin Strom Unveils the Mirrored Force Resonance Red

Armin Strom has masterfully fused its revolutionary resonance technology with a bold, contemporary aesthetic in the new Mirrored Force Resonance Red. Limited to just 15 pieces worldwide, this rare masterpiece introduces a striking off-centre guilloché dial in vibrant red. By pairing traditional hand-crafted artistry with the brand’s signature open-worked design, this timepiece breathes dynamic new energy into Armin Strom's celebrated dual-balance mechanism, creating a captivating dialogue between classic hand-finishing and cutting-edge mechanical architecture.

The brilliant red dial is hand-crafted on a traditional, manually operated rose engine lathe, engraving a radiating pattern that catches and plays with light in captivating reflections. Encircled by black azuré (蝸形紋) chapter rings and topped with faceted, floating index markers, the dial's layout creates a stark, three-dimensional contrast that maximizes both visual depth and legibility. Housed in a polished 43 mm stainless steel case, the movement's technical architecture is framed by anthracite-coated bridges and paired with a dark grey Alcantara strap—ensuring that the vibrant red dial and the synchronized dance of the resonance mechanism remain the undisputed center of attention.

At the heart of this technical marvel lies the in-house Calibre ARF21, a hand-wound movement that integrates two completely independent movements within a single calibre. Connected via Armin Strom's patented Resonance Clutch, the two opposing balance wheels transfer vibrations to enter and maintain a perfect state of harmonic resonance. This physical synchronization significantly improves chronometric stability and rate consistency over time. To let wearers witness this horological phenomenon in action, a pusher at 2 o'clock activates a flyback mechanism, resetting both independent seconds hands to zero simultaneously so their perfect synchrony can be monitored in real-time.

Every millimeter of the Mirrored Force Resonance Red showcases Armin Strom's uncompromising dedication to haute horology standards, featuring meticulous hand-polished bevels, perlage, circular graining, and mirror-black polished screws. On the reverse side, the main plate features technical inscriptions rendered in three-dimensional relief, rising directly from the metal's surface. As is tradition for the Swiss manufacture, each watch is assembled twice to guarantee absolute precision. For collectors seeking the pinnacle of independent Swiss watchmaking, this 15-piece limited edition represents a perfect harmony of mechanical science and artistic expression.

 

View Watch Gallery
Image 1






  

 

View More
JULY 02 2024    |    Novelties

A timepiece unveiling the aesthetic technique of a finely hand-decorated movement.

For the final titanium 41mm, three-hands limited edition with rubber strap, Romain Gauthier presents a timepiece with a partially open dial, unveiling a portion of the entirely hand-decorated movement.

C by Romain Gauthier Titanium Editions are modern timepieces with a sporty design that encloses a titanium movement whose hand-finishing prowess can be admired on the case-back. This time Romain wanted the stunning features of this movement to be easily visible just by looking at the watch, even when worn. By opening the dial, he reveals the beauty of the mechanism inside, bringing a technical aesthetic to this timepiece, which until now has featured a full dial.


This partially open dial is particularly reminiscent of the history of the brand's very first timepiece, the Prestige HM, which evolved to reveal the seconds-hand mechanism on its sister caliber, the Prestige HMS.

Unveiled in 2021, the C by Romain Gauthier caliber was the result of more than 16 years of know-how acquired through the brand's development and its manufacture, while reflecting Romain's creative freedom with a modern and youthful design.

Technical in nature, casual in style and free in spirit, the Freedom collection has enabled the creation of this contemporary caliber. The significance of C by Romain Gauthier lies in its creative approach to reinforce the notions of continuity with its concept and design, in reference to the Continuum. Reflecting a vision of the future for a timepiece which is part of Romain Gauthier's philosophy, and which opens the door to new horizons.

During its creation, it was clear to Romain that the case had to harmonize with the movement. It had to be contemporary and uncluttered. But not only that – comfort, ergonomics and the choice of materials also contributed to the design of this timepiece with the decision to use Grade 5 titanium. The dial, in sapphire for this edition, adds to the consistency of the piece and evokes a sense of continuity, as no circle completes the time indication.

Inspired by the finger bridges style, the design of the movement follows the watchmaking history of the Vallée de Joux but with a modern approach, reflecting Romain’s vision of the evolution of tradition.

Romain Gauthier presents the sixth edition of the caliber in titanium in a limited edition of 88-pieces and engraved “1 of 88” on the back of each movement.

 

View More
APRIL 09 2026    |    Watches and Wonders 2026

Celebrating 200 Years of Moritz Grossmann with the TREMBLAGE Gold

The year 2026 marks a momentous milestone for Moritz Grossmann as we celebrate the 200th anniversary of our founder’s birth. Moritz Grossmann was not only a master horologist but a visionary scientist and author who forever changed the landscape of Glashütte watchmaking. To commemorate his bicentenary, we are proud to unveil the TREMBLAGE Gold anniversary edition, a tribute that bridges his 19th-century spirit with the pinnacle of modern artisanal watchmaking.

This exceptional release introduces two limited editions, crafted in 750/000 rose gold and 950 platinum, with each variant strictly limited to just eight pieces worldwide. The soul of these timepieces lies in the solid rose gold dial, which has been meticulously hand-engraved using the rare "tremblage" technique. This traditional method involves a master engraver using a specialized burin to create a multi-directional, finely textured matte surface, resulting in a mesmerizing play of light that serves as a backdrop for the raised, hand-polished numerals.

The movement powering these anniversary models is the exquisitely finished Calibre 100.1 manual-winding movement. In a direct nod to the founder's legacy, the balance cock features a unique hand-engraved "1826," marking the year of Grossmann’s birth. Every component, from the heat-annealed brown-violet screws to the hand-carved pillars and German silver plates, reflects our commitment to "Schönstes deutsches Handwerk"—the finest German craftsmanship.

With the TREMBLAGE Gold edition, we do not simply replicate history; we evolve it. These watches embody the same pursuit of technological perfection and aesthetic brilliance that Moritz Grossmann championed two centuries ago. We invite you to discover these masterpieces, which stand as a testament to a heritage that continues to inspire every movement we create and every hand-finished detail we produce in our Glashütte manufactory.

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4       
View More
ENDLESS DISCOVERY IN YOUR INBOX
Join our mailing list to receive insider updates on our latest collections, invites to private events, and other personalized offerings.