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

MARCH 17 2026    |    Novelties

Greubel Forsey Unveils Final Editions of the Balancier Convexe S² in White and Black Ceramic

Greubel Forsey introduces the final and most exclusive editions of the Balancier Convexe S²: one in black ceramic with 5N red gold, and one in white ceramic, each strictly limited to 11 pieces.
These editions conclude a calibre developed through five years of mechanical and architectural exploration, with production set to cease permanently in 2026.

The Convexe case (41.5 mm) and movement were conceived as a single architectural whole, integrating Greubel Forsey’s signature 30° inclined balance wheel system as the visual and chronometric centre. The openworked movement features 301 components, including a 68‑part escapement platform, and is 
powered by two rapid-rotation coaxial barrels delivering a 72‑hour chronometric reserve.

Finishing remains uncompromising: frosted titanium bridges, polished bevels, hand‑finished countersinks, and meticulous transitions — even on invisible components.

Two Final Interpretations
Black Ceramic & 5N Red Gold
A dramatic contrast of dark architecture framed by ceramic, with red gold adding warmth and sculptural depth.The interplay of matte and polished surfaces enhances the piece’s three‑dimensional form

White Ceramic
A purist, graphic expression that highlights the structural geometry of the movement through light and shadow.The monochromatic case offers clarity, openness and a distinctly technical aesthetic.

Both editions preserve the characteristic S² display: suspended hours/minutes bridge, small seconds, and sector power‑reserve indication beneath a curved sapphire crystal.

This launch marks the concluding chapter of the Balancier Convexe S²’s five‑year evolution — not an iteration, but a final statement. As of 2026, Greubel Forsey will begin a gradual shift toward an almost entirely new collection, retiring earlier calibres with intention and ceremony rather than quiet discontinuation.

 

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4  Image 5  Image 6 Image 7  Image 8  
View More
NOVEMBER 19 2025    |    Novelties

gérald genta Introduces Gentissima Oursin 41 with Meteorite Dials

gérald genta continues its legacy of audacious elegance with the launch of two new references in the Gentissima Oursin collection: Blue Meteorite and Green Meteorite. These timepieces mark a bold evolution of the iconic design first imagined by Mr. Gérald Genta in 1994, inspired by the delicate yet resilient form of the sea urchin.

A Design Born from Nature and the Cosmos
The Gentissima Oursin 41 features a 41mm sandblasted Grade 5 titanium case, meticulously set with 234 white gold beads, echoing the organic geometry of the sea urchin. At its heart lies a dial carved from a fragment of meteorite—a material born from the stars—making each watch a unique, one-of-one creation. The natural crystalline structure of meteorite ensures that no two dials are alike, offering collectors a truly rare expression of artistry.

Sporty-Chic Meets Haute Horlogerie
Combining rubber straps and titanium architecture with luxurious gold accents, the Gentissima Oursin 41 is designed for everyday wearability without compromising sophistication. A curved sapphire crystal, faceted with a subtle octagonal profile, protects the dial and enhances its dynamic character. Gold hands filled with Super-LumiNova featuring a pink hue—a tribute to Mr. Genta’s favorite color—ensure legibility and elegance.

Mechanical Excellence
Inside beats the Zenith Elite GG-005 automatic movement, boasting a 50-hour power reserve, 4 Hz frequency, and an 18K yellow gold oscillating mass, visible through a sapphire caseback. With 50m water resistance and a comfortable rubber strap, this timepiece is as practical as it is artistic.

 

View Watch Gallery
Image 1 Image 2Image 3 Image 4Image 4Image 4
View More
APRIL 01 2025    |    Watches and Wonders 2025

Armin Strom Introduces The One Week Skeleton

The Armin Strom One Week Titanium Skeleton, an openworked masterpiece now fully skeletonized to reveal the intricate heart of its mechanics, combines striking design with precision engineering. Encased in lightweight titanium grade 5, it balances strength with comfort, providing a feeling of lightness that makes it easy to wear all week long.

The Armin Strom One Week Titanium Skeleton is a showcase of skeletonization, a technique that is rooted in Mr. Armin Strom’s philosophy and heritage. He sought to enhance depth and three-dimensionality while avoiding see-through to maintain elegance.

The 2023 One Week was already openworked by nature, but this version goes even further, removing more material to highlight the movement’s complexity. Few watches combine openworking and skeletonization at this level. The small seconds dial is skeletonized, revealing the power reserve level and the escapement wheel for a 3D mechanical animation. The mainplate and the barrels are also skeletonized enhancing aesthetics. Thanks to this skeletonization, the power reserve indicator is highlighted as well as the cone mechanism, reminiscent of ancient pocket watches. A major highlight is the case back, offering a mesmerizing view of the entire mechanism.

With a 7-day power reserve, this watch keeps time accurate for an entire week without needing winding. The hand-finished details reflect the level of craftsmanship behind its design. Limited to 100 pieces, the One Week Titanium Skeleton offers a refined, functional timepiece that blends robustness and comfort in a minimalist package.
 

View More
MARCH 26 2026    |    Watches and Wonders 2026

Born of Tradition: Moritz Grossmann Unveils the HAMATIC Silver-Plated by Friction Anniversary Edition

The year 2026 marks a historic milestone for the Moritz Grossmann manufactory in Glashütte, as it celebrates the 200th birthday of its visionary founder and namesake, born on March 27, 1826. A genius watchmaker, scientist, author, and initiator of the German Watchmaking School, Grossmann profoundly shaped the craft of horology and the fate of his hometown. Rather than merely imitating historical concepts, the modern manufactory honors his legacy by blending his cutting-edge philosophy with modern engineering. This dedication to technological perfection and exceptional aesthetics cements its place among the world's elite elite watchmakers.

To commemorate this bicentennial occasion, the brand has unveiled the HAMATIC Silver-Plated by Friction anniversary edition. This special timepiece introduces exclusive design details that pay tribute to the brand's origins, including an "1826" engraving on the balance cock and a vintage 1875 "M. GROSSMANN" logo on the dial. For the first time on a Hamatic model, clean Arabic numerals represent the hours, gracefully stepping in to replace the Roman numerals traditionally favored in previous iterations.

At the heart of the watch lies the exquisite manufactory calibre 106.0, which features a highly effective automatic winding system driven by a pendulum-style hammer weight. This "hammer automatic" mechanism masterfully reinterprets a historical concept with contemporary engineering, incorporating custom features like stop seconds for precise time setting and hand-finished decorations. The movement also proudly mirrors Grossmann’s original ingenuity through traditional hallmarks, such as a large balance wheel, raised screws, and fine handcrafted hands made of blue annealed steel.

The standout aesthetic achievement of this anniversary edition is its rare "silver-plated by friction" dial finish. This painstaking, entirely manual technique requires a master artisan to delicately brush the dial surface with specialized pastes and powders to achieve a fine-grained, velvet-like texture that softly diffuses light. Set in an elegant white gold case paired with a blue kudu leather strap, the HAMATIC Silver-Plated by Friction will be released on March 26, 2026, and is strictly limited to just 18 pieces worldwide.

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.