The new Armin Strom System 78 Gravity Equal Force (part two)

The new Armin Strom System 78 Gravity Equal Force perpetuates the Swiss brand’s reputation for innovation and mechanical know-how. This new watch features a redesigned barrel, a Geneva wheel, newly designed involute teeth, high-end finishing and handsome aesthetics. Angus Davies examines this timepiece closely and discovers an exemplar of haute horlogerie.

Armin Strom System 78 Gravity Equal Force

When Serge Michel (Founder of Armin Strom) and Claude Greisler (CEO and Technical Director) chose to create the new Armin Strom System 78 Gravity Equal Force, they wanted to create a watch endowed with extraordinary technical virtuosity, an attribute for which the brand is renown, high-end finishing and comparatively keen pricing.

Image – some of the many parts used within the System 78 Gravity Equal Force

Claude Greisler worked on concepts, considering ideas which would deliver technical advancement. While Claude wanted the new System 78 Gravity Equal Force to be one of the most affordable means of owning an Armin Strom, he also wanted the new watch to push the boundaries of horological innovation.


At the heart of the Armin Strom philosophy is a wish to reveal many components ordinarily hidden from view. However, while the new Armin Strom System 78 Gravity Equal Force upholds the brand’s philosophy ‘we show what we make’, it does not adhere to the conventional open-worked model.

Armin Strom System 78 Gravity Equal Force

Unlike some open-worked watches from competing brands, the dial is not adapted from an existing main plate. Instead, it has been created from the outset to showcase its barrel, micro-rotor, hand-setting mechanism and a myriad of other small components. This approach delivers superior torsional rigidity, aiding reliability.

Armin Strom System 78 Gravity Equal Force

Secondly, while the time indications on some open-worked watches can become lost in a sea of micro-components, the System 78 Gravity Equal Force presents the hours, minutes and seconds on a highly legible off-centre dial.

By adopting this approach, the new Armin Strom System 78 Gravity Equal Force sidesteps the weaknesses found on many open-worked watches while still indulging curious eyes with views of various components in motion. Moreover, the free disclosure of parts confers a visual lightness which proves most becoming.

There are a multitude of smile-inducing design features on this watch, yet Armin Strom has not got carried away, successfully enriching the design without burdening the aesthetic with superfluous or fussy detail.

I will touch on many of these design elements hereafter.

The front of the watch

There are three key elements to the front of the watch, the micro rotor positioned at 1 o’clock, the barrel located at 5 o’clock and the off-centre hour and minute display at 9 o’clock. Consistent with previous Armin Strom models, such as the Gravity Water, the micro-rotor and spring barrel share similar dimensions, providing a degree of symmetry to the dialscape.

Image – dial awaiting fitting

The time indication is shown on a dial at 9 o’clock. Prospective buyers can choose from black, blue or white dial options. The Bernese-style hands are open-worked with truncated tips, articulating time with a clear voice and exuding a notable degree of elegance. Arabic numerals, presented in an eye-catching font, grace the snailed hour track. A minuterie hugs the periphery of the dial, facilitating the interpretation of the minutes.

Image – Bernese hands, produced in-house

Armin Strom has equipped the dial with a snailed small seconds display. This is integrated within the main dial, ensuring the dialscape remains clean and uncluttered. In my opinion, a separate seconds indication would have marred the otherwise uncluttered appearance of the model’s dialscape.

Three, twin-arm bridges emanate from the right flank of the case, inspired by the architecture of vintage pocket watches. They are functional, holding the micro-rotor, the hand-setting mechanism and spring barrel, respectively. The upper surface of each bridge is straight-grained, while the exterior edges feature gleaming bevels executed by hand. What is most remarkable is that the interior surfaces of the bridges, with their two converging angles, marry up perfectly, the glorious consequence of an artisan’s deft hands. The finishing is remarkable and is consistent with watches costing substantially more than the new Armin Strom System 78 Gravity Equal Force.

Image – dial-side bridges post finishing, awaiting installation.

Wherever the eyes roam, there are beautiful episodes of finissage to discover. For instance, adjacent the micro rotor, clouds of overlapping perlage can be seen adorning the main plate. Furthermore, a crescent-shaped aperture atop the barrel confers sight of the Geneva wheel (see part one for more details).

Each part sits resplendently against a frosted main plate. Indeed, the muted nature of the frosted main plate, acts as a foil for the neighbouring components, allowing them to come to the fore and bask in attention.


The case

Hitherto, the smallest Armin Strom case measured 42.00mm (Pure Resonance). The Swiss brand has clearly recognised that tastes have changed in recent years and have therefore chosen to house the new Armin Strom System 78 Gravity Equal Force within a 41mm stainless steel case. The resultant appearance of this new watch looks neater and should suit a broader array of would-be wearers.

Armin Strom System 78 Gravity Equal Force

The ‘lip’ has been a key feature found on all Armin Strom models. Many of the brand’s clients love the lip, myself included, as it provides a point of difference. Moreover, the lip allows the owner to personalise the watch with their initials. With the advent of the new Armin Strom System 78 Gravity Equal Force, the lip is neater and curves downwards. The new lip is more discreet, engaging with new audiences while at the same time indulging the desires of the brand’s loyal fan base.

The crown features contemporary fluting and looks neater than its forebears. The lugs have been pared back, eschewing mass and upholding the brand’s penchant for open-worked detail. Armin Strom has endowed the case with a seemly blend of highly polished and brushed surfaces.

Unlike some Armin Strom watches which feature alligator straps with prominent horn-back markings, the System 78 Gravity Equal Force is supplied on a sumptuous black alligator leather strap with subtle graining. The character of this latter strap is more reserved and unassuming. The prospective purchaser can choose between an ardillon buckle or, for a supplementary fee, a stainless steel double-folding clasp.

A key attribute of any Armin Strom watch is that the owner can remove his cherished timepiece from his wrist, turn it over and become immersed in a world of mechanical manoeuvres and flawless finishing. The new Armin Strom System 78 Gravity Equal Force perpetuates this reputation, sating the desires of the most mechanically inquisitive minds.

The movement

The Armin Strom Caliber ASB19 is a Manufacture movement. While the Maison freely admits to sourcing cases, dials and straps from specialist firms, it has always been known for making fine movements within the confines of its Biel atelier.

Armin Strom System 78 Gravity Equal Force

Image – Caliber ASB19 (recto view)

The term ‘vertical integration’ seems very apt when discussing the array of in-house competencies at Armin Strom. Main plates, bridges, screws, pinions, barrels and levers are just a few of the parts made in the Manufacture (see part one for more details).

Armin Strom System 78 Gravity Equal Force

Image – Caliber ASB19 (verso view)

Armin Strom is one of only a few companies which make automatic movements equipped with a micro-rotor. When contrasted with a conventional oscillating mass, a micro-rotor affords superior views of the movement, a quality which is evident when appraising the Caliber ASB19.

The barrel is a revolutionary design. It casts aside convention and ingeniously rethinks the role of the arbor. With the ‘motor barrel’, the barrel housing remains locked after winding and the arbor transmits energy to the gear train. The arbor is more stable, it rotates in a precision jewel, suffers less side to side motion and moves more precisely when driving the gear train.

Unusually, the barrel, in combination with a Geneva wheel / stop works ensures that a modulated flow of energy is sent to the regulating organ, ensuring the amplitude of the balance is within the optimal range (see part one for more details). The power-reserve of the Caliber ASB19 is 72 hours.

The gear train wheels feature newly designed involute teeth, enhancing the efficiency of the power transmission. This improvement represents the culmination of six years of research and development, highlighting the brand’s obsession with horological advancement.

Image – variable inertia balance

The System 78 Gravity Equal Force’s raison d’être is precision. This is not only manifest with the model’s innovative barrel and Geneva wheel, but also with the specification of the balance. The Caliber ASB19 features a variable inertia balance. Unlike a conventional balance equipped with an index adjuster, the rate on this balance is altered by adjusting the four screws affixed to the balance wheel. By tightening or loosening the screws, the moment of inertia is altered, causing the movement to run faster or slower. By adopting this latter approach, the hairspring is not nipped between any curb pins and breathes more freely, aiding precision. Moreover, Armin Strom has positioned the timing screws in recesses within the rim of the balance wheel, mitigating air turbulence and, by default, further aiding precision.

Technically, the Armin Strom System 78 Gravity Equal Force is incredibly refined and will undoubtedly fulfil the desires of the most pernickety horophile. However, beyond its mechanical probity, the Caliber ASB19 is also enriched with many examples of high-end finishing.

The main plate has been subject to ruthenium treatment and features frosting and perlage. The dark tones of the main plate recesses provide a backdrop for the gear train and balance, augmenting their visual allure. Similar to the recto-positioned bridges, the balance cock incorporates exquisite anglage, including internal angles executed by hand.

Image – bevelling external angles of gear train bridge (prior to electroplating)

The bridges and three quarter plate are rhodium plated and adorned with Côtes de Genève motif. The gear train bridges are designed to mimic the shape of bridges found on pocket watches of yesteryear. The jewel and screw sinks are polished. All screws have chamfered rims, polished slots and mirrored tops. A cartouche is affixed to the movement, proclaiming the movement’s unique reference number.

Image – bridge adorned with Côtes de Genève

While the Armin Strom System 78 Gravity Equal Force is intended to be one of the brand’s more affordable watches, it is unquestionably an exemplar of haute horlogerie.

Closing remarks

Since Armin Strom opened the doors to its Manufacture in 2009, the company has always sought to supplant watchmaking norms with technical advancement. When other high-end watch brands obsessed over the tourbillon, seeking ever more complex enhancements to Breguet’s invention, the brand from Biel developed its patented resonance clutch spring and achieved greatness by looking at precision from an alternative viewpoint.

More recently, Armin Strom chose to set aside the usual circular gongs found in the age-old  minute repeater by unveiling a grand complication featuring eccentrically shaped, three dimensional gongs. The resultant sound vindicated its decision and justified its protracted efforts.

Now, the Bernese brand has sought to optimise precision by modulating the force serving the regulating organ. The motor barrel rethinks the role of the mainspring and the arbor, delivering a superior, consistent source of power to the gear train. Moreover, Armin Strom has surmounted various technical obstacles in order to pair an automatic movement with a stop works. This latter technical highlight restricts the rotation of the barrel, ensuring the gear train rotates when the torque curve is flattest. When it comes to the specification of the new Armin Strom System 78 Gravity Equal Force, everything is wonderfully considered and confers an impressive degree of precision.

Armin Strom System 78 Gravity Equal Force

However, beyond its timekeeping talents, this watch also looks incredible. Quite simply, Armin Strom has created an achingly gorgeous watch. The proportions of the case and dial are sublime. The three double-spoke bridges presented dial-side are attractive and incorporate exquisite hand-drawn internal angles.

The finishing of the verso plane of the movement is equally impressive. The perlage, anglage, Côtes de Genève, ruthenium treatment, rhodium treatment, polished jewel and screw sinks and pristine screws, each finished to an exalted standard, perfectly illustrate the no-compromise composition of this watch. With an asking price of CHF 16,900 this latest creation from the Bernese Manufacture delivers a heady mix of precision, beauty, craftsmanship and value, qualities which will become immediately apparent after the briefest association.

Further reading

Technical specifications

  • Model: Armin Strom System 78 Gravity Equal Force
  • Reference: ST19-GEF.90.AL.M.35
  • Case: Stainless steel; diameter 41 mm; height 12.65 mm; water resistance 3ATM (30 metres) sapphire crystals to the front and back
  • Functions: Hours; minutes; small seconds
  • Movement: Caliber ASB19; automatic movement; contains 28 jewels; power reserve 72 hours; 202 components
  • Strap: Genuine black alligator leather strap paired with a stainless steel pin buckle. A stainless steel double-folding clasp is available as an optional extra.
  • Price: CHF 16,900 / US$ 15,600 (RRP as at 20.11.2019)


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