The saying "if it isn't broken, don't fix it" is rarely applied by watchmaker Stephen McDonnell, the creator of MB&F's most complex watches, enhanced through his innovative technological breakthroughs.
Fans of the remarkable MB&F watches, responsible for models like the LM Perpetual and LM Sequential EVO from 2015, will be delighted to know that Stephen McDonnell has returned. This time, McDonnell elevates the functionality of his award-winning chronograph caliber by adding a flyback feature. However, in the new, refined release of 33 pieces, MB&F has placed all the complications in a more classic Legacy Machine capsule. The LM Sequential Flyback, floating in a platinum case with a sky-blue dial, is a watchmaker's dream.
The LM Sequential EVO, released in 2022, was MB&F's first chronograph and 20th caliber, and in true MB&F style, it was meant to be simply mind-blowing. Turning to longtime friend MB&F and watch wizard Stephen McDonnell, he created the LM Sequential EVO, which brought ordinary chronographs to light.
Before becoming a watchmaker, McDonnell received education as a theologian, so his approach to creating a chronograph mechanism was unconventional. Rather than asking "how", he sought to define all the situations in which a chronograph could be useful. The chronograph mechanism, equipped with two column wheels linked to a single oscillator that could be activated simultaneously, opened a window to countless timing possibilities. Complementing the role of the traditional control lever, McDonnell equipped the mechanism with a revolutionary Twinverter switch.
The ability to instantly switch between chronograph modes enhanced the versatility of this complication, allowing for four different timing modes - independent, simultaneous or split-seconds, sequential or lap, and cumulative (very useful for timing chess matches) - and inverting the start/stop status of each chronograph. Don't miss Bryce's detailed account of the various ways these four modes can be applied.
With 585 components, a suspended oversized balance wheel, and a vast number of timing options, MB&F decided to place this insanely complex creation in a more robust 44mm EVO zirconium case, equipped with a shock absorber and water-resistant up to 80 meters. Advertised by the brand as a case for outdoor adventures, I'm not sure many LM Sequential chronograph owners would admit to using it for cross-country.
Classic Case, Flyback Mechanism
In addition to the already mind-bogglingly complex LM Sequential mechanism, a flyback has appeared - a function originally intended for pilots. Developed in the 1930s for aviators, the flyback or "retour en vol" function eliminated the time wasted on stopping, resetting, and restarting the chronograph, which could accumulate and lead to dangerous navigation errors. The flyback solved this problem by simultaneously pressing a single button to stop, reset, and restart.
It turns out the initial prototype of the LM Sequential EVO, developed by McDonnell, included a flyback but was postponed due to the additional time required for research and testing. After two years of testing and absolute secrecy, the LM Sequential Flyback is ready, which means there are now five separate timing modes.
Although the dial layout is identical to the LM Sequential EVO, the new model uses a more classic Legacy Machine environment. Still bristling with five pushers, the 44mm platinum case is 18.2mm tall, with longer screwed lugs and features brightly polished surfaces with matte side surfaces. Another distinctive feature is the engraved inscriptions on the lower pushers, which now read FLYBACK. Despite the screw-down crown, the case has lesser water resistance - 30 meters.
The LM Sequential Flyback equips both chronographs with a flyback function and works as follows: the left chronograph is activated by the start/stop pusher at the "10 o'clock" position and the reset/flyback at "8 o'clock"; the right chronograph operates similarly, but with pushers at the "2 and 4 o'clock" positions. The fifth pusher on the case at the "9 o'clock" position is the Twinverter or "magic button", which controls both chronograph systems and acts as a binary switch, inverting the current start/stop status of both chronographs. If both chronographs are stopped, pressing the magic button causes them to start simultaneously, and if both are running, the Twinverter stops them. The elapsed time is displayed on four additional dials: two 30-minute counters at "11" and "1 o'clock" and two larger 60-second counters at "9" and "3 o'clock".
More traditional LM features can be appreciated on the dial with its impressive balance wheel, suspended above four chronograph counters with white lacquered rings and blued hands. Unlike the EVO, the domed white lacquered subsidiary time dial at "6 o'clock" with Roman numerals is positioned above the two chronograph counters rather than below them and is tilted toward the owner thanks to conical gears. The sky-blue platinum creates a beautiful celestial background.
One mechanism with two independent chronographs demands great power. McDonnell's ingenuity addresses this with innovative and patented jeweled vertical clutches, which reduce friction and prevent the flyback from resetting to zero. A special jeweled roller was developed for the flyback mechanism, allowing the Sequential caliber to surpass traditional chronographs in energy efficiency and precision.
The fully integrated manual wind double flyback chronograph mechanism now consists of 619 components. Thanks to a double mainspring, it maintains a 3 Hz frequency and a 3-day power reserve (the power reserve indicator can be seen at the bottom with a blued hand). Beautifully adorned with hand-finished darkened bridges (NAC finish) contrast with polished bevels and vibrant rubies.
Availability and Price
The LM Sequential Flyback Platinum is released in a limited edition of 33 pieces and retails for 188,000 Swiss Francs, 192,000 Euros, or 218,000 US Dollars (all prices excluding taxes). More detailed information can be found on mbandf.com.