Understanding the Armin Strom Gravity Equal Force and its Technical Innovations

Armin Strom is among these independent watchmakers that not all watch lovers know… But clearly, they should, because Armin Strom is doing great things! In 2016, it reinvented the resonance concept with its own and impressive take on the phenomenon with the Mirror Resonance watch and its two balances connected by a spring to accentuate the effect of resonance on the movement. Last year, in 2019, to celebrate its 10th anniversary, the brand launched another masterpiece, combining two impressive complications, the Minute Repeater Resonance. This was just the beginning of the brand’s strategy.

Now, to demonstrate its ability to create complex but not necessarily inaccessible watches, Armin Strom is launching a new entry-level collection named “System 78”. The first model in this sub-collection is the Gravity Equal Force and it really is an interesting watch and mechanical development. Its focus, besides the very cool design, was to bring back chronometry in these modern-looking pieces.

Besides the looks that are reminiscent of an ultra-modernized pocket watch, with Armin Strom’s usual entirely openworked architecture – a signature element of all the brand’s timepieces – there are multiple innovations on the movement side, such as a declutch stop-work and motor barrel. All of this to ensure a very stable flow of energy to the escapement and accuracy during the entire duration of the power reserve.

How does the Armin Strom Gravity Equal Force work?

The barrel is the device that stores energy in a watch movement. However, the force delivered by the barrel is irregular. Strong torque is provided when it is fully wound, then it slowly wanes throughout the duration of the power reserve. This affects the rate of watches because balance wheels are not perfectly isochronous. Taming power has therefore been an ongoing horological quest. The delivery of consistent power is the idea that inspired the Armin Strom Gravity Equal Force.

Armin Strom has created a special Geneva stop-work, just like some rare hand-wound movements, but specifically adapted to an automatic movement. To avoid low torque, the first turns of the barrel are not used. In addition, this new ‘declutch stop-work’ allows the mainspring to slip in the barrel (patent pending). When you get a traditional automatic watch that has not been worn for some time, its spring is completely unwound. A little movement of the rotor will bring it back to life, however, this would not be enough to tighten the spring sufficiently and to take advantage of the movement to its full capacity. With the Gravity Equal Force, as soon as the watch starts and the seconds hand moves, you know the spring delivers enough power.

The development of this sophisticated mechanism was the occasion to re-engineer the whole barrel construction, opting for a “motor barrel,” to enhance the movement efficiency, taking advantage of the stable and precise arbour to drive the going train.

In our latest in-depth video, we’ll be talking to Claude Greisler who will explain all the technical and visual details behind this new and fascinating Armin Strom Gravity Equal Force.

More details in our review of the Armin Strom Gravity Equal Force and at www.arminstrom.com.