MB&F Rethink The Chronograph With New LM Sequential EVO

The chronograph is a pretty straightforward complication, used to time things that need timing, like laps around the track, or more realistically, boiling noodles and making sure your kid stays in timeout for the appropriate length. Start, stop, and reset, sometimes with a split seconds hand, sometimes with flyback functionality, but largely adhering to the same basic formula. The chronograph gets a another implementation today courtesy of MB&F, and movement designer,  Stephen McDonnell in the form of the LM Sequestional EVO, a watch with dual sequential chronographs operating independently, linked via “Twinverter”, and each utilizing a vertical clutch and gear train with a single escapement at their confluence. It’s novel, and it’s wild, and we’d expect nothing less from the same mind that gave us the LM Perpetual. 

The LM Sequential is the first MB&F watch to get a seconds hand of any kind, and being MB&F, they implemented it (them) in a way that’s never been done before. Each sits within a large ring sub dial that dominate the left and right halves of the dial, and each sits at the center of a mirrored chronograph system that are capable of working independently of the other, or in concert with each other. Each gets their own set of actuators, and they are linked by a 5th button called the Twinverter (more on that in a minute). A 30 minute totalizer sits atop both of the timing seconds dials, and a single dial at 6 o’clock displays the time in minutes and hours. A power reserve indication for this hand wound movement is placed on the back of the movement.


Being a Legacy Machine, the balance wheel is suspended over the dial by a polished bridge. The balance staff is connected to the escape wheel and pallet fork underneath the timing seconds rings, but above the dial plate. As with all LM watches, there’s plenty of depth and movement to enjoy on the dial side, and while it may hamper at-a-glance legibility, it’s all situated in a watch that makes sense once you’re accustomed to the layout. For instance, the time is quick to discern when you know where to look for it, and the oversized timing seconds allow for a greater level of precision in use (though, to be fair, they are only graduated to the second, so an actual precise measurement is limited to your interpretation of the space between each tick). 

The chronograph mechanisms designed by Stephen McDonnell address some of the inefficiencies in the typical chronograph, and represent a true step forward in the development of this complication. McDonnell redesigned the vertical clutch to sit within the main gear train to eliminate amplitude fluctuations between active and inactive modes of the chronograph. This has done away with the friction spring and the flutter of the timing seconds hand we find on typical chronographs. Each chronograph gets its own column wheel, one turning clockwise, the other counterclockwise, and the Twinverter allows the wearer to toggle between operating modes that open the complication to a variety of potentially handy use cases.

Firstly, each chronograph can be operated independently, as you would any other chronograph. Each side gets a start button, and a stop/reset button as you’re no doubt accustomed to. There’s also a simultaneous mode, allowing both chronographs to be started at the same time, with a single press of that Twinverter button at 9 o’clock. They can then be stopped together, again with a press of the same button, or individually, with the press of the stop button associated with either. You can also start one side, then press the Twinverter button to stop the one running, and start the other simultaneously. The 30 minute totalizer will keep track of the running time of either side when actuated. Basically any combination of using the two chronographs together or separately is possible here. Check out the video below to see it in action. 

All of this is placed with the LM EVO case, with flex ring making for a relatively practical sport watch as it’s pretty comfortable, and has 80 meters of water resistance. Well, as practical as a 172,000CHF sports watch can be, I suppose. The case is made of zirconium, and measures 44mm in diameter, and 18.2mm in thickness thanks to the steeply domed crystal. The legs are shaped ergonomically and the rubber strap integrates to the case, so it actually wears quite comfortably on the wrist.

The LM Sequential EVO is as visually dramatic as it is mechanically, with much of the chronograph works exposed on the dial side. The timing surfaces are black, and the bottom plate of the dial is either atomic orange or black, with the levers and gears occupying the space between. It’s a similar vibe to the equally stunning LM Perpetual. 

As impressive as this watch is, I can’t help but wonder how complications such as this might be expressed within the confines of their Horological Machine collection, which would have to structure the complexity within an unexpected form factors found there. 

This watch represents the MB&F’s 20th caliber in just 17 years. A rather remarkable feat considering they design these things largely from the ground up to fit their conceptual goals. This journey is being documented, and the first 15 years are profiled in their book: MB&F: the First Fifteen Years – a Catalog Raisonné available on their website right here

Learn more about the remarkable LM Sequential EVO from MB&F, and don’t miss the podcast we record with Max Busser last year right here.

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Blake is a Wisconsin native who’s spent his professional life covering the people, products, and brands that make the watch world a little more interesting. Blake enjoys the practical elements that watches bring to everyday life, from modern Seiko to vintage Rolex. He is an avid writer and photographer with a penchant for cars, non-fiction literature, and home-built mechanical keyboards.