The remarkable concept of Moritz Grossmann’s ATUM Backpage sprung from the desire to showcase every aspect of this stunning and unique movement in a delicate and refined manner.
The result was achieved by configuring what can be termed a “mirrored movement”. In theory, Moritz Grossmann’s calibre 107.0 is a mirror image of its calibre 100.1. In practice it is much more complicated but, thanks to the dedication and skill of the technical team, this ingenious calibre construction and configuration makes it possible to observe the winding and hand-setting mechanism as well as the stop-balance device through the display back.
This timepiece is both captivating and technically impressive offering something for the watch connoisseur and collector in one piece.
DESIGN CHALLENGES & DETAIL
On the dial side, a full minute scale and an hour arc from 11 to 5 o’clock serve as the framework for the moving calibre presentation. The applied hour markers and numerals in gold match the case colour. The recessed small seconds ring features an impressive bearing for the seconds-hand arbor: a gold chaton indicating the Backpage. With its subtle colour palette, the dial serves as a stage for the brilliant choreography of the movement within.
The blue dial with blue annealed hands contrasts vibrantly against the platinum case. The rose-gold version with a delicate grey dial and brown-violet hued hands radiates cultivated poise and taste.
On the case back side, the contiguous train bridge is decorated with Glashütte ribbing and ennobled with hand-engraved calibre inscriptions. Interesting insights are provided by the cut-outs above the oscillation system and parts of the balance stop spring as well as via the generous aperture above the manual winder with pusher ensemble.
The larger dimensions of the 2/3 plate necessitated design changes for the balance cock and the escape-wheel cock. The solution to develop cantilevered geometry of the escape-wheel cock creates a balanced accent in the overall architecture of the movement. Additionally, the High-Artistic finish of the two components showcases the beautiful hand engravings, bevels, and chamfers. Other fine details include the polished minute-wheel bridge and the lavishly finished dial train with its spoked and chamfered wheels.
Case: 750/000 Rose Gold
Hands: Manually crafted, annealed to a brown hue
Movement: Manufacture calibre 107.0, manually wound, adjusted in five positions
No. of parts: 230
No. of jewels: 24, of which 7 in screwed gold chatons
Escapement: Lever escapement
Oscillator: Shock-resistant Grossmann balance with 4 inertia and 2 poising screws, Nivarox 1 balance spring with No. 80 Breguet terminal curve, Gerstenberger geometry
Balance: Diameter 14.2 mm, frequency: 18,000 semi-oscillations/hour
Power reserve: 42 hours when fully wound
Functions: Hours and minutes, subsidiary seconds with stop seconds, Grossmann winder with pusher
Special features: Shock-resistant balance with inertia and poising screws, impulse pin integrated in rim; flat balance spring; balance staff with integrated safety roller; index adjuster with Grossmann micrometer screw; plate movement with 2/3 plate on dial side, frame pillars and separately removable clutch winding mechanism; visible hand setting train on the back side of the movement; frame parts in untreated German silver; Grossmann winder with pusher and stop seconds; raised gold chatons with pan-head screws; remodified Glashütte stopwork with backlash; mainspring barrel with bilateral jewel bearings for optimised power management in the low-torque range; ARCAP train wheels; proprietary escapement with 18-tooth escape wheel; balance cock and crown wheel, intermediate winding wheel and ratchet wheel with stopwork on the modified spring barrel bearing with a gold chaton in the ratchet wheel; dial train wheels spoked and beveled, beneath polished bridge
Operating elements: Crown in precious metal, for winding the watch and setting the time, pusher in precious metal for starting the movement
Case dimensions: Diameter: 41.0 mm, height 11.35 mm
Movement dimensions: Diameter: 36.4 mm, height 5.0 mm
Case: Three-part, precious metal
Dial: Solid silver, baton hour markers in precious metal
Hands: Manually crafted, steel, annealed to a brown hue
Crystal/display back: Sapphire crystal, antireflective coating on one side
Strap: Hand-stitched alligator strap with prong buckle in precious metal