The Grönefeld 1941 Remontoire was certainly one of the watches we were excited to see at this year’s Baselworld. We know the Grönefeld brothers very well, and love their work. They burst into fame with their Parallax Tourbillon winning the GPHG Best Tourbillon in 2014, but have been active making interesting and horologically exciting watches for a while. Their One Hertz is their first offering, and still remains an interesting option for those keen to explore the Independents.
Rationale for remontoire d’egalité
The Grönefeld brothers grew up, and still live in the Dutch town of Oldenzaal. Their grandfather Johan and father Sjef were both watchmakers and were responsible for the town’s church clock mechanism at Saint Plechelmus. This clock, like many tower clocks used in church towers feature a 30 seconds remontoire mechanism. The remontoire is perhaps the most elegant method to ensure constant force to the escapement.
Why is a remontoire required? In order to provide for longer power reserves, most tower clocks have a reserve or 7 days and some even can go for a whole month between windings, the power source needs to be big. In a tower clock the power to the train is usually a weight which is hoisted up the tower and allowed to fall. As it descends, it supplies power to the train. Although this force remains fairly constant (after all gravity is a constant force), it is subject to imperfections in the gear train and variations in lubrication. Remember that in a huge clock from that era, operated on components which were large, heavy, and not finished. In order to smooth out these irregularities, a small spring is used to provide power to the train. This spring is placed within the wheel train, and is wound in fixed intervals by the falling weight. This spring is known as a remontoire.
In a spring driven clock or watch, the power source is the mainspring. This mainspring is by necessity is large, long and strong. As it unwinds, the torque follows Hooke’s Law, and depletes over time. When fully wound, the torque is very high, and when near depletion, the torque is much reduced. This variation in torque affects the escapement’s isochronism. Similarly, the remontoire is a small spring installed within the wheel train. By nature, this remontoire spring is small, it is able to supply a more constant torque to the train, but it also goes from full to depleted quickly, and needs to be rewound often. The mainspring’s power is used wind the remontoire. So that the movement can run for the full power reserve of the mainspring, while attaining the constant torque supplied by the smaller remontoire.
Remontoires in wrist watches were first introduced by F.P. Journe in his Tourbillon Remontoir D’egalité. Journe fitted his tourbillon with a one second remontoire, which as the name implies discharges and rewinds once every second. This provides a near constant force to the tourbillon escapement. The system uses the remontoire to power a seconds morte mechanism. Journe followed up with his even more elegant Chronomètre Optimum. A similar technique is used in the Lange 31 and the Lange Zeitwerk. But the principal reason for the remontoire in the Langes is to ensure that the huge power of the mainspring, required because the Lange 31 has a power reserve of 31 days, and the Zeitwerk has to have sufficient power to ensure a clean jump of all 4 digits instantaneously. In SIHH this year, Lange added the Richard Lange Jumping Seconds to her list of watches with remontoires, and utilize the staccatto effect of the rewind of the remontoire to power the seconds morte. A similar remontoire, executed differently is also used in the Jaeger LeCoultre Geomatic True Second.
Grönefeld 1941 Remontoire
Required reading: Introduction to the Grönefeld 1941 Remontoire. The Pre-Basel press release information.
Case, dial, hands
The case is a new case design for the Grönefelds. Dubbed 1941, it is sculptured, and visually it gives the impression that it is light, as the lugs are hollowed out. The case is polished at each stage of cutting or milling to ensure that the shapes and contours of the case is retained. This is an interesting manufacturing process for the cases. The detailing on the case is quite beautiful, and is a result to this attention to detail.
The 39.5mm watch comes in two metal options: one in 5N red gold 18K White Gold. It is interesting that the 18k white gold version has a high palladium content. and this allows the case to be bare, without the typical rhodium plating used on many white gold cases. This feature is not unique, as Lange also adopts the same practice. The case is just 10.5mm thick, and makes for a svelte looking watch, graceful under the cuffs. This is the smallest wristwatch made by Grönefeld to date. The One Hertz and the Parallax Tourbillon being 43mm x 12.5mm.
The dial is solid sterling silver, and is punctuated with an opening to show the regulator which is not unlike the governer of a minute repeater, and is used to regulate and prevent the slap resulting from the power of the mainspring each time it is released to rewind the remontoire. The remontoire is rewound once every eight seconds. As one gazes on the watch, the governer can be seen spinning once every 8 seconds. Each spin lasts several revolutions, and creates somewhat of a spectacle on the dial side.
The hands are elegant, long sweeping design, and flame blued. If one observes carefully, the minute hand can be seen to move one little step every the remontoire is rewound, that is once every 8 seconds.
Movement: Calibre G-05
This is where the magic happens. The movement is developed by the Grönefeld brothers with the assistance from Andreas Strehler. This is a natural partnership as the brothers and Strehler were working close together in Renaud et Papi in the 1990s.
The main plate is made of brass, and the bridges and cocks holding the train is made of stainless steel. The use of stainless steel bridges is a Grönefeld signature, and is also seen in their One Hertz and their Parallax Tourbillon. The bridges were made for them by Renaud et Papi, and those used in the Remontoire is made by Strehler. Strehler’s manufacture in Sirnach is also suitably equipped for small volume production of complicated plates, bridges, wheels, pinions, springs and small components used for the Remontoire.
All design, assembly and finishing is done in-house in the Grönefeld facilities in Oldenzaal. The finishing is particularly punishing as stainless is a much harder material than the usual brass or maillechort used for bridges. The special finish designed by the brothers also make the task challenging. The center of the bridges are frosted, and a raised lip near the edge is polished and anglaged. This finishing work is exemplary.
One may criticize that the bridge layout is very haphazard and messy, and one would be right that they do not seem to be harmony in the flow of design chi. But the movement is pure masochismo, full of testosterone and raging to go. It is designed from a watchmaker’s perspective to showcase the virtuoso performance of finishing.
The Grönefeld 1941 Remontoire is an extremely interesting watch. It has presence. A great beauty. But it also have the quirkiness of the Dutch. OK, lest we offend a nation, let’s just say it has the quirkiness of the Grönefeld brothers. And if one knows both Bart and Tim, this is not a fault, but a great praise.
One cannot argue with the technical. The cold stainless steel bridges is made more human with the somewhat messy bridge layout. The superior technical virtuosity of the movement is tampered with the sensuous curves of the case. A study in contrasts? Yes, but one that works. We feel this is an excellent representation of the excellent work afforded by the brothers Bart and Tim Grönefeld.
The competition for remontoire based watches is a rarified few. We have mentioned the F. P. Journe Chronomètre Optimum (S$125,200 in rose gold). We have also touched on the JLC Geophysic True Second (S$25,900/€17,400 in pink gold), the Lange Richard Lange Jumping Seconds (€78,000). These are perhaps rather direct comparisons. But all feature a seconds morte system, which the Grönefeld Remontoire lacks. Grönefeld’s own seconds morte watch is the One Hertz, which utilizes dual trains to achieve the jumping seconds. In addition, the Journe and the Lange both have power reserve indicators of some sort. The Chronomètre Optimum has a regular power reserve dial, while the Richard Lange Jumping Seconds has the binary end of power indicator.
One might also draw comparison to the Lange 31 (€115,000), the Lange Zeitwerk (€58,100 in pink gold). The Lange 31 features an unusually long power reserve of 31 days, and the Zeitwerk features a novel jumping hour, jumping minute digital indication.
Grönefeld watches are unique in their use of stainless steel bridges, so they stand on their own in that regard.
The idea of the remontoire is an intriguing one. It is a technically elegant solution to taming the force of the mainspring and to provide a constant force to the escapement. The design of the Grönefeld Remontoire is interesting as well. The story behind the inspiration is lovely and charming. The visual aesthetics of the Remontoire is excellent, the brothers have come a long way from the awkward looking early One Hertz watches. The bridges, as mentioned is somewhat haphazard in their layout, making the back view of the watch busy, but yet it retains a certain charm. One that hints of honesty. Like spilling one’s guts for all to see. The movement is certainly finished par excellence. And our respect for the brothers is immense, having met and know them for many years. These are honest craftsmen, practicing the craft with love and passion. Hence the Grönefeld 1941 Remontoire gets our Editor’s Choice for Top 5 Watches from Baselworld 2016.
Grönefeld 1941 Remontoire – Specifications
Technical specifications of the manual wound movement Calibre G-05 8 Seconds Remontoire
Diameter: 32,0 mm
Thickness: 5,5 mm
Number of parts: 258 parts
Number of jewels: 36 jewels, partially set in solid gold chatons
Power reserve: 36 hours with constant force (stop system)
Remontoire: to optimize time keeping a small hairspring is wound every 8 seconds to guarantee a constant force for the escapement. A complex satellite gearing mechanism with hypocycloidal gears, twin ball bearings, pinions and jewelled levers, achieve this.
Balance wheel: variable-inertia balance wheel with four white gold timing screws (diameter 10 mm)
Frequency: 21.600 vibrations/hour
Balance spring: free sprung with Phillips terminal over coil curve with triangle hairspring stud
Escapement: jewelled Swiss lever
Main plate: spotted and ruthenium electroplated brass main plate
Bridges: stainless steel, bevels polished by hand, micro-blasted centre, circular grain on the top rims to highlight the bridges shapes and engravings, bas-relief engraved Grönefeld logo, number of jewels and eight seconds remontoire
Hacking seconds: in setting mode the hacking seconds mechanism will be activated
Display: Central Hours and Minutes, Small Seconds at 6 o’clock, Governor speed regulator at 9 o’clock
Case and Dial specifications
Number of case components: 66 parts
Case material: white gold Au750/Pd150 (Non Rhodium plated) or red gold Au750 5N
Domed sapphire crystal on the front with hard antireflective coating on both sides
Flat sapphire crystal on the back with hard antireflective coating on both sides
Case back engraving: Grönefeld and the individual number
8 White gold security screws
Diameter: 39,5 mm
Thickness: 10,5 mm
Water resistance: 3 atmospheres – 30 meters – 100 feet
Crown: white gold (Non Rhodium plated) / red gold engraved with logo
Dial: Sterling Silver 925, frosted and satin-grained surfaces
Hands: extended ‘lancette’ hands, flame-blued steel and mirror polished centres, small poised seconds hand
Strap: hand-sewn ostrich leather with white gold or red gold buckle engraved with Grönefeld logo