I have a recollection of Claude Greisler, technical director at Armin Strom, mentioning the term “Mirrored Force Resonance” to me at one of the many watch shows around the world and telling me to watch out for it. The intriguing concept was since lost among the glut of press releases we receive every day at WorldTempus… until now. The small, discreet but fully-fledged manufacture in Bienne positively blows the competition out of the water at this year’s SalonQP by presenting a brand-new in-house movement that uses a new, patented, technology developed exclusively by the brand.
Although the concept of resonance has been known in the field of horology for some time, dating back to the use of pendulums in clocks, very very few watchmakers have incorporated it into timepieces, probably because of the extreme precision required to achieve resonance within the small confines of a watch movement. Not to be confused with oscillation, which is the physical motion that provides the power in a quartz watch, for example, and has also been used in mechanical watches such as the TAG Heuer Mikrogirder, the phenomenon of resonance involves two oscillating bodies (in this case, two balance wheels) vibrating at exactly the same frequency. To achieve this, one balance wheel acts as the “exciter”, transmitting its energy to the other (the “resonator”), which absorbs it with the result that the two bodies become perfectly synchronized. To achieve this, the distance between the two bodies must be calculated to perfection.
The specific benefits of resonance in a mechanical watch movement are the stabilization of the movement’s going rate, conservation of energy and a reduction in the negative effects of shocks. The latter benefit is particularly interesting, since in the case of a shock to one of the two balance wheels, the other one will automatically speed up to compensate before the oscillation of the two balance wheels once again reaches equilibrium. In the case of the new Armin Strom Calibre ARF15, this takes just a few minutes, while 10 minutes is required to achieve resonance when the watch is wound up from standstill.
Mirror, mirror on the wall, who is the greatest of them all?
Although there are other watch movements on the market that use the phenomenon of resonance, the new Calibre ARF15 by Armin Strom works differently. It is the only one whose construction has a physical connection between the two balance wheels, in the form of a patented resonance clutch spring that has taken the brand over two years to develop because of its highly complicated shape. This spring drives the symmetrical seconds display, which is arranged vertically on the dial. Compared with other resonance movements, this spring connects not the balance wheels themselves but the balance spring studs, the exact point on the balance that receives the impulses from the pallet fork. The addition of this spring also offers a much better visual appreciation of the resonance phenomenon, while the two balance wheels rotate in opposite directions to each other (hence the “mirror” in the mirrored force resonance).
This exciting new technology debuts today at SalonQP in London in an 18-carat red-gold case with a diameter of 43.4mm. The new watch would not be an Armin Strom if it did not show off all the beauty of this new movement design to the full, complete with its meticulous fine watchmaking finishing, through one of the brand’s typical skeleton dials and a transparent sapphire crystal case back.
Also true to the Armin Strom ethos, the Mirrored Resonance Fire model is exclusive (a limited edition of 50 pieces) but by no means excessive in terms of its price, particularly given the precious metal case and the years of development work involved. The 67,000 Swiss franc price tag is entirely reasonable for such a technological breakthrough.
