Moritz Grossmann Benu Tourbillon Review

by Jan 19, 2020Limited Edition, Moritz Grossmann

Moritz Grossmann’s manufacturing facility was originally closed and liquidated when he passed away suddenly in 1885, however with such an important history, it seems a shame to have lost it forever. 

This is exactly what trained watchmaker Christine Hutter thought in 2008, when she discovered the original Glashütte brand and had it re-registered, bringing back Moritz Grossmann’s legacy 120 years later.

As with many of the modern Moritz Grossman range, the Benu Tourbillon (which is the most exclusive of quite a large range of Benu watches) was conceived using traditional concepts, principals and ideologies, but using modern methods of manufacture and re-imagined horological functions.

The inspiration behind the new Benu Tourbillon movement is summarised by Grossmann very well below:

The calibre 103.0 movement of the BENU Tourbillon represents a new concept with an array of surprising solutions. To translate into reality the aspirations of Grossmann’s watchmakers with respect to precision, efficiency, and aesthetics, classic principles of horological design were critically reviewed and pivotal movement functions optimized

Moritz Grossmann Benu Tourbillon

Moritz Grossmann Benu Tourbillon

Face & case

At 44.5mm wide, the 3 part case is white gold, with a very narrow bezel, which makes the dial appear even bigger beneath the sapphire crystal. 

The dial itself is fairly busy, although not overcrowded and on first glance it doesn’t appear so.  The watch I am reviewing has a black dial, with white detail; although there is also a white/cream dial Moritz Grossman call argenté, which inversely features black detail.  Dials are made from solid silver.

A 60 minute marker ring surrounds the face on a slightly elevated level, displaying slightly smaller markers for every 12 seconds, with multiples of 5 up to 60 minutes shown in neat Arabic numerals; ideal for accuracy using the the sweeping minute hand.  At 6 o’clock, the numbers and markers between 25 and 35 minutes are missing, due to the aperture which allows the large 3 minute tourbillon to show its beating heart.

The missing numbers are however not lost, they are in fact shown in the centre of the dial on a scale from 25 to 35 minutes, just above the minute hand rotation point, by use of a patent-pending dual minute display, which extends the minute hand backwards, allowing an accurate reading of minutes.

Above the minute arch is the Moritz Grossmann Glasshute logo and on either side of the central minute arch, there are another 2 sub dials.  On the left, the stop seconds and on the right the hours.  Both sub dials feature chapter rings, with their respective numerals only shown at 12, 3, 6 and 9 o’clock.

Going back to the main feature within this piece, the 3 minute tourbillon is big.  The tourbillon cage itself has a diameter of 16mm and therfor the aperture in the dial must be in the region of at least 20mm wide.  The cage features a V-shaped balance bridge, which requires only two posts, for which another patent is pending.

The tourbillon used within the Benu was designed and built according to Alfred Helwig’s original concept, inspiring Grossmann’s caliber designers in their development phase.  Alfred Helwig was a teacher at the German School of Watchmaking (established by Moritz Grossmann in 1878) from in the early 1900’s, who applied for a patent for the flying tourbillon in 1920. In 1922, he also designed and built a unilaterally suspended five-minute tourbillon. Originally, the tourbillon served the purpose of offsetting gravity-induced rate deviations in pocket watches that were worn vertically. 

The tourbillon cage is freely suspended from a newly designed, cantilevered, hand-engraved cock made of German silver.  The hairspring is also visible and actually attached upside down to the lower cage base beneath the balance.  The end result is a truly distinctive way to achieve functional purity. 

Another patent pending design used in the Benu, is the stop seconds function at the balance wheel rim, which features a pivoting fine-hair brush.  The hair used is actually human hair – Moritz Grossmann’s own Christine Hutter’s hair.  An elastic human-hair brush can easily glide past the triangular posts and gently brake the balance at the circumference of its rim smoothly.

The crown is large and quite flat, with deep ridges for grip.  The pusher is somewhat smaller and flat, situated closer to the back of the watch.

Turn the piece over and the sapphire crystal allows everything to be seen through the screw down back.  

There is a large plate covering around 2/3 of the watch movement, with a few distinct cogs poking through it, as well as some large blued screws and various mounting points.  The rear mounting and workings of the tourbillon can be seen, as well as other integral working cogs. 

There are various engravings on both the edge of the case back and on the main plates.

Moritz Grossmann Benu Tourbillon Case Back

Moritz Grossmann Benu Tourbillon Case Back


The movement is the in house manually wound calibre 103.0, adjusted in five positions.

With 245 parts and featuring 30 jewels (4 of which in screwed gold chatons), it features a lever escapement, 3 minute tourbillon with stop seconds and shock-absorbed Grossmann balance.

At 16.0 mm, the cage revolves once every three minutes, anti-clockwise when viewed from the dial side.

Running at 18,000 semi-oscillations per hour, one should expect 72 hours of running time once fully wound.

Moritz Grossmann Benu Tourbillon Crown & Pusher

Moritz Grossmann Benu Tourbillon Crown & Pusher


The strap is in black hand stitched alligator, with a butterfly clasp in 750/000 gold.

Moritz Grossman can clearly be seen engraved across the width of the buckle.

Moritz Grossmann Benu Tourbillon Strap & Buckle

Moritz Grossmann Benu Tourbillon Strap & Buckle

Other stuff

The Benu Tourbillon featured in this hands on review is actually the most exclusive version of the watch, limited to only 10 pieces worldwide – the white gold, reference MG-000779 with a black dial, however there are 2 other versions available:

BENU Tourbillon rose gold, reference MG-001354, argenté dial, limited to 25 pieces worldwide.

BENU Tourbillon white gold, reference MG-000004, argenté dial, limited to 50 pieces worldwide.

There is also a BENU Tourbillon in white gold with a blue dial, reference MG-001173, which can be purchased by Aircraft owners only.  

Moritz Grossmann Benu Tourbillon on the Wrist

Moritz Grossmann Benu Tourbillon on the Wrist

Our verdict

The Moritz Grossmann Benu Tourbillon is really a lovely looking watch that I would definitely like to spend more time with.

The size is about right for my preference and the design, although mainly understated could be considered a bit in your face with the large, mesmerising tourbillon that is difficult to take your eyes off.  

The weight is good and at only 13.8mm thick, it’s surprisingly thin and likely unobtrusive when it comes to fitting under cuffs (although you probably would want to show it off anyway).  

I am told that should a purchaser of a Benu prefer their own hair to be used for the brush, this could be possible – quite a nice personalisation if you ask me, especially since my ginger locks may well be more visible than the likes of blonde!

With only a limited number of 10 pieces available in the configuration shown, and only a few more in each of the other versions, it is unlikely you see one while doing your weekly food shop and especially with a price tag of £160,000.

I haven’t actually seen a rose gold Benu in person, but perhaps this could take the Tourbillon to another level of class.