About the Tudor 91210N
Announced at Baselworld 2015, the 40mm dial Tudor North Flag timepiece comes in two variants, stainless steel bracelet here, and a leather strap variant, and is the very first Tudor with an in-house movement: Manufacture Calibre MT5621 automatic calibre, a monumental milestone in the history of the company.
It also sported many other firsts too for the Montres Tudor brand:
- First in-house movement that is Contrôle Officiel Suisse des Chronomètres (COSC) certified: Manufacture Calibre MT5621. Ceramic ball-bearings are used in the centre of the bi-directional rotor for long-life use,
- First exhibition display caseback,
- First power reserve indicator, via a spinning disc at 9 o'clock on the dial (70 hours power reserve via a single barrel),
- First use of ceramic, in the mid-bezel,
- First use of silicone hairspring (Si14), in a free-sprung (variable inertia oscillator) balance wheel held in place by a traversing double-bridge. Frequency = 28,800 beats/hour or 4Hz,
- First anti-magnetic Tudor curtsy of the silicone hairspring.
The case is one single 316L stainless steel (SS) monocoque case, 50mm from lug-to-lug, with a ceramic mid-bezel, topped by another 316L SS ring, for superb durability. Crown is signed with the Tudor Shield logo and is a screw-down type. It has three functions: when unscrewed and in first position, it winds the watch (power reserve disc moves upwards); second position is date change; third position is hacks the movement (arrests the seconds hand) for adjusting the hour and minute hands. (Some sources speculate that the crown itself might be made of titanium due to the different colour metal, but this has not been confirmed). The date change is instantaneous at midnight, and the entire watch is 100m water resistant. The case is satin brushed except for the very bottom edge, which is polished, and the rim of the SS ring above the ceramic mid-bezel is also polished. The exhibition caseback has a fluted/coin edge design.
The 316L SS bracelet has a unique deployment clasp with a Tudor Shield motif, using four ceramic ball bearings for long life use, and all H-styled links are satin polished except the top and bottom of each interlink, which is polished. However due to the integrated lugs the spring bars (12mm), only a few custom strap makers will be able to make straps for this timepiece.
Though the timepiece sports vintage homages, the Tudor Ranger II (12 and 6 Arabic numerals, case shape), and Gérald Genta (integrated sloping lugs, case shape), are the strongest vintage vibes, the watch is nonetheless a modern, new, machine made timepiece with an advanced calibre. The calibre has nary any embellishments, as the timepiece is echoing an industrial design code, which works perfectly for the aesthetics of this tool watch.
The yellow accents on the watch give it a tool vibe, with a nice contrasting style to the black dial, which has white hour and minute hands and indices, printed lettering, and the white background of the date window at 3 o’clock. Watch has yellow seconds hand, yellow printed hour indications on the rehaut (with white printed minute indications), and yellow printed power reserve (with a white printed power reserve hand on the moving disc).