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

APRIL 07 2026    |    Watches and Wonders 2026

The HM Pietersite: A Tribute to the Spirit of Exploration and the Art of the Ultra-Thin

Arnold & Son presents two new evocative versions of its ultra-thin HM model, featuring dials crafted from Namibian pietersite. Often called the "stone of storms," this decorative mineral belongs to the chalcedony family and was first discovered by Sid Pieters in the early 1960s. Each unique dial displays delicate, swirling patterns that recall the turbulent skies and foaming waves of Cornwall, the English birthplace of founder John Arnold. This design pays tribute to the ingenuity of the legendary watchmaker while celebrating the spirit of those who maintain their course in a challenging world.

The designation "HM" was intentionally chosen to reflect the watch's focus on displaying only hours and minutes, while simultaneously serving as a historical nod to the British Royal Navy. In naval tradition, HM stands for "His or Her Majesty’s," a title that appeared in the 17th century and was later formalized as HMS. By transposing this reference to watchmaking, Arnold & Son connects the precision of modern horology with England's maritime history, specifically the era when John Arnold’s marine chronometers enabled the exploration of new lands.

Encased in a choice of 18-carat red gold or stainless steel, the HM Pietersite is a masterpiece of elegance and restraint. The case measures a refined 39.5 mm in diameter with a remarkably slim profile of just 7.82 mm. To complement the dreamlike, diaphanous patterns of the pietersite dial, the timepiece is paired with a matte ink-blue alligator leather strap and a traditional pin buckle crafted from the same metal as the case. These limited editions are produced in extremely small quantities, with only 8 pieces available in red gold and 18 in steel.

At the heart of this timepiece lies the ultra-thin, in-house A&S1001 manual-winding calibre. Visible through a sapphire crystal case back, the movement is a showcase of luxury finishing, featuring a rhodium-plated main plate with circular graining and bridges adorned with radiating Côtes de Genève. Despite its slender height of only 2.70 mm, the movement offers exceptional performance with a generous 90-hour power reserve. Every detail, from the snail-finished wheels to the blued screws with polished heads, reflects the most exacting standards of Swiss watchmaking.

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4       
View More
OCTOBER 16 2025    |    Novelties

Moritz Grossmann Unveils TOURBILLON Titanium and TOURBILLON Tremblage: Tradition Meets Modernity

The tourbillon has long been regarded as one of the most fascinating complications in the history of watchmaking. Moritz Grossmann now reinterprets this horological icon with two extraordinary creations: TOURBILLON Titanium and TOURBILLON Tremblage. These timepieces embody the manufactory’s philosophy of blending traditional craftsmanship with contemporary aesthetics.

The TOURBILLON Titanium combines the technical sophistication of a flying three-minute tourbillon with the modern appeal of a titanium case. Its solid silver dial, adorned with a fine grain d’orge guilloche pattern, reflects the artistry of hand-guided engraving techniques. The result is a watch that is both lightweight and visually striking, offering a perfect balance of durability and elegance.

The TOURBILLON Tremblage, on the other hand, celebrates the beauty of historical handcraft. Its warm rose-toned dial is meticulously engraved using the traditional tremblage technique, creating a unique matte texture that softens light and enhances depth. Paired with a white gold case, this model exudes timeless sophistication while showcasing the manufactory’s dedication to artisanal excellence.

Both models are powered by the hand-wound calibre 103.0, featuring a flying three-minute tourbillon and patented innovations for precision timekeeping. Every component is finished by hand, from the engraved plates to the polished screws set in gold chatons, reflecting the highest standards of Glashütte watchmaking. These creations are more than timepieces—they are works of art that unite heritage and modernity in perfect harmony.

View Watch Gallery
Image 1 Image 2Image 3 Image 4Image 5
View More
JULY 01 2025    |    Novelties

Armin Strom Unveils the Mirrored Force Resonance Ice Blue – A Tribute to Precision and Craftsmanship

Armin Strom proudly presents the Mirrored Force Resonance Ice Blue, a limited edition timepiece that exemplifies the brand’s dedication to horological innovation and artisanal excellence. With only 15 pieces available worldwide, this release marks a bold evolution in the art of synchronized timekeeping.

The watch features a striking ice blue sunray guilloché dial, crafted using a traditional hand-operated rose engine lathe. Its off-center layout and radiant finish create a captivating play of light beneath the sapphire crystal, while beveled and polished indexes and hands add depth and movement to the design.

At the core of this timepiece is the manually wound Caliber ARF21, a technical breakthrough in resonance watchmaking. Armin Strom’s patented clutch system connects two balance wheels, allowing them to oscillate in opposite directions and synchronize for enhanced precision and stability. Twin seconds counters provide a visual representation of this resonance effect, and a pusher at 2 o’clock resets the counters, offering a clear demonstration of the mechanism’s accuracy.

The movement is hand-finished to haute horology standards, with Geneva stripes, perlage, and black-polished screws visible through the transparent case back. Each watch is assembled twice to ensure both mechanical integrity and flawless finishing.

Encased in a 43 mm stainless steel case and paired with a dark blue Alcantara strap, the Mirrored Force Resonance Ice Blue is a celebration of independent Swiss watchmaking and the science of movement.
 

View Watch Gallery
Image 1 Image 2  
View More
MAY 07 2026    |    Novelties

Traditional Watchmaking Elevated: DANIEL ROTH Introduces the Extra Plat Platinum

In the refined sphere of independent watchmaking, DANIEL ROTH has introduced a sophisticated new expression of its Extra Plat collection, elevating the rarity of the line while retaining an understated and disciplined elegance. Rooted in the firm belief of its legendary founder that a thin dress watch represents the ultimate epitome of functional elegance, this model is meticulously designed from the ground up to balance modern sophistication with time-honored craft. Cloaked in 950 platinum—a noble metal long synonymous with rarity and traditional savoir-faire—the watch establishes a quiet yet unmistakable presence on the wrist that will immediately resonate with serious connoisseurs.

The defining silhouette of this timepiece remains the signature double-ellipse case, an iconic geometry originally created by master watchmaker Daniel Roth to beautifully frame complex horological mechanisms. To complement this distinctive shape, downward-sloping lugs have been elegantly integrated to ensure optimal wrist comfort while providing a handsome architectural contrast against the light-tan calfskin leather strap. The dial base is forged from solid white gold, displaying a mesmerizing pinstripe guilloché texture executed entirely by hand using a traditional rose engine. Each line is individually carved with masterful control over depth and spacing, beautifully bordered by a gold minute disc finished with a classic filet sauté edge and sharp black typography.

Beneath this stunning facade lies the core of the timepiece: the ultra-thin, hand-wound manufacture Calibre DR002, fully developed and assembled at La Fabrique du Temps Louis Vuitton under the expert guidance of master watchmakers Michel Navas and Enrico Barbasini. Tasked with striking the perfect balance between chronometric precision and a generous power reserve within a slim 3.1 mm structure, the watchmakers increased the movement's frequency to 4 Hz. To sustain this high frequency without sacrificing energy efficiency or structural stability, the calibre incorporates a specially refined balance wheel featuring a variable-inertia geometry and adjustable counterweights.

An open sapphire caseback reveals the true artistic discipline of the manufacture, where technical engineering and aesthetic restraint seamlessly converge. The movement's bridges are decorated with demanding hand-finishing details, most notably the internal angles which are rendered in a rare, rounded bercé form. Requiring at least twice the execution time of a standard flat bevel, this traditional decoration involves polishing a precise curved radius along the edges to create a brilliant, uniform profile. Shaped and hand-polished in-house using a traditional cabron tool, these components reinforce the brand's unwavering commitment to its guiding philosophy: "La Montre Objet d'Art".

 

View Watch Gallery

Image 1

Image 2
Image 2
Image 2
 
View More
JUNE 23 2026    |    Novelties

Arnold & Son Unveils the Perpetual Moon 41.5 Steel "Colours of the Moon"

Arnold & Son has unveiled its new "Perpetual Moon 41.5 Steel Colours of the Moon" collection, a series of highly exclusive, limited-edition timepieces inspired by the changing celestial hues of Earth's natural satellite. Detailed in the official release document, "ENG_A&S PM 41.5 Steel Colours of the Moon.doc", the collection features three distinct versions—the Blue Moon, Golden Moon, and Red Moon—each celebrating a unique atmospheric or seasonal phenomenon that alters the Moon's appearance and has fascinated civilisations throughout history.

Reinterpreting the iconic Perpetual Moon collection, these new models introduce a 41.5 mm stainless-steel case that balances horological exclusivity with everyday versatility. In a watchmaking first, Arnold & Son has applied a pioneering Physical Vapour Deposition (PVD) treatment directly onto precious mother-of-pearl. This innovative process creates deep, shifting reflections across the dials and moon-phase skies, showcasing the natural organic layers of the material with patterns that recall the flowing grain of Damascus steel.

The astronomical precision of the moon phase is enhanced by Super-LumiNova hidden beneath the colored mother-of-pearl moon disc, accompanied by hand-painted luminescent constellations of Cassiopeia and Ursa Major—a poetic tribute to historical mariners who relied on them for navigation. Bringing this celestial mechanics to life is the in-house A&S1512 manual-winding calibre. This movement provides a generous 90-hour power reserve and displays meticulous luxury finishes, including radiating Côtes de Genève and a secondary moon-phase indicator, all visible through the sapphire crystal case back.

Each of the three references is paired with a matching hand-stitched alligator leather strap and secured with a stainless-steel pin buckle. To maintain their extreme exclusivity, production is strictly limited to just 18 pieces per version.

 

View Watch Gallery
Angelus Instrument de Mesures

Angelus Instrument de Mesures

Angelus Instrument de Mesures

Angelus Instrument de Mesures
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.