SPECIFICATIONS:
MB&F Horological Machine No. 9
Flow, red gold
Horological Machine n°9 ‘Flow’ is
available in two versions:
• ‘Road’ version with a
speedometer-style dial;
• ‘Air’ version with an
aviation-style dial.
Each version is now available in
titanium (two editions of 33 pieces
each) or in red gold (two editions of 18
pieces each)
Movement: Manual-winding with two
fully independent balance wheels with
planetary differential, frequency of
18,000bph, single barrel with 45-hour
power reserve, hours and minutes on
vertical dial display
Case: New limited editions in 57mm x
47mm x 23mm red gold assembled in
three segments with patented three-
dimensional gasket, 18 pieces each,
with a NAC movement and rhodium-
plated balance wheels (“Air” version) or
rhodium-plated movement with red
gold balance wheels (“Road” version),
water resistant to 30 meters, five
sapphire crystals
Strap and buckle: Hand-stitched brown
calf-leather strap with custom-designed
titanium or red gold 5N+ folding buckle
MB&F GILDS ITS HM9 FLOW
BY MICHAEL THOMPSON
A YEAR AFTER MB&F INTRODUCED ITS HYPER-AERODYNAMIC
HOROLOGICAL MACHINE NO.9 FLOW, the pioneering independent maker
expands the HM9 series with the HM9 Flow Red Gold.
MB&F made the debut HM9 series in two titanium editions of thirty-three
pieces, and likewise this new variation comes in two limited editions, but only
numbering eighteen pieces each, all with a new, rich red gold aura.
Echoing the original HM9, the new red-gold editions split their
personalities based on dial style and accents. Each eighteen-piece red
gold edition is either an HM9 Air or an HM9 Road. Where the Air version
features an aviation instrument style, a darkened movement and rhodium-
plated dual balance wheels, the Road version shows its colors with a
classic speedometer, a rhodium-plated movement and red gold dual
balance wheels.
DUAL REGULATORS
The MB&F HM9 movement is one of very few dual regulator calibers in any
case shape to feature two fully independent balance wheels. But unlike other
multi-balance movements, the HM9 engine deliberately avoids a resonance
effect (a type of harmonic mind meld among two linked oscillators) in
favor of a system using the two balance wheels to obtain “discrete sets
of chronometric data” translated by the differential to produce one stable
averaged reading. The balances are individually impulsed and separated to
ensure that they beat at their own independent cadences of 2.5Hz (18,000
bph) each.
Echoing the dual-regulator style of the MB&F Legacy Machine No.2,
the HM9 features a consciously more aerodynamic profile, with two satin-
finished air scoops seamlessly mounted alongside the two balance wheels,
each set within sapphire-topped pods. Between the pods, the movement’s
unusual planetary differential gear ensures that the dial, showing hours and
minutes, remains precise, even though the dial is set at a 90-degree angle to
the movement.
You might recall that due to its unusual aerodynamic shape, Büsser and
Friends needed to divide the watch’s 57mm-wide titanium case along two
axes and devise an unprecedented three-dimensional gasket. The gasket
solved one of several conundrums for MB&F during the design phase for
HM9, which several case makers originally deemed impossible to construct.
But despite that hesitation, company founder Maximilian Büsser told
International Watch last year that the final HM9 design was nonetheless
true to his initial idea.
“I am so proud of the team because the final piece is practically identical
to my initial concept design,” Büsser said. “That usually never happens. I
guess either the engineers were even smarter than usual, or I was just more
difficult and adamant not to allow modifications.” The price for the HM9 Red
Gold is $198,000.
WINTER 2020 | INTERNATIONAL WATCH | 67