Three Ways to Solve the Same Problem: The Eternal Battle Against the Mainspring

The three watches look so different right? They come from different eras, different brands, and their design cues seem to have little in common.

But look closer (as John Mayer would say),  inside their movements, and you will discover that they are all trying to solve the same problem: the mainspring.

Mechanical watches have an inherent problem. When a mainspring is fully wound, it delivers its strongest force. As the energy is gradually released throughout the day, the output torque decreases. This variation can affect the amplitude of the balance wheel, and ultimately the stability of timekeeping.

In an ideal world, the balance should receive a consistent amount of energy at every moment. The goal is to prevent it from starting with excessive strength and gradually losing force as it runs.

It sounds like a simple requirement. Yet for centuries, countless watchmakers have devoted themselves to fighting against this very problem of mechanical watches.

Today, let us look at how three brands and the watchmakers behind them approached the challenge.

1. A. Lange & Söhne: The Ambition of a Revival

I have never been much of a tourbillon person. I can appreciate the work involved, but a large opening in the dial often seems to ask for more of my attention than I want to give it. The original A. Lange & Söhne Tourbillon “Pour le Mérite,” which I’ll call the PLM here, is an exception. 

A. Lange & Söhne’s first-generation Tourbillon “Pour le Mérite”

The tourbillon is plainly visible, yet the rest of the watch still holds together. I find myself looking at the whole dial rather than just the mechanism turning inside it.

Part of the attraction is knowing when this watch appeared. Lange’s main production building was destroyed in an air raid in 1945, and the family business was nationalized in 1948. The name then disappeared for more than forty years. 

Walter Lange and Günter Blümlein began rebuilding the company in 1990, presenting its first new collection on October 24, 1994. The PLM was one of those first four watches. It is easy to forget how much had to happen before there was even a collection to show.

From left to right: Günter Blümlein, Walter Lange and Hartmut Knothe

Seen in that context, the PLM feels like a remarkably ambitious place to begin. A revival brings expectations of its own: collectors want some connection to the old company, but they also need a reason to take the new watches seriously. For me, the PLM makes that connection through its mechanics. 

The fusee-and-chain transmission draws on centuries of watchmaking, while the difficulty of fitting it into a wristwatch gave the returning Lange something substantial to contribute.

The L902.0 movement was developed with Renaud & Papi, the complications specialists whose name will be familiar to anyone interested in this end of watchmaking. Inside the 38.5 mm case of the yellow gold reference 701.001 are a tourbillon and a chain assembled from 636 individual components. 

 

That number is impressive enough, but the scale is what makes it difficult to picture. A system familiar from pocket watches had to be made small enough to fit inside a wristwatch of quite restrained dimensions.

Fortunately, the principle is easier to grasp than the construction. Think of using a wrench: with the same force from your hand, a longer handle produces more torque. The fusee uses that relationship to compensate for the mainspring as it unwinds. 

A chain connects the barrel to a cone-shaped fusee. When the mainspring is fully wound and pulling hardest, the chain acts on the narrow part of the cone, giving it a shorter lever arm. As the spring weakens, the chain moves toward the wider part, increasing the leverage.

The Working Principle of the Fusee and Chain Mechanism

The spring still loses torque as it runs down. The changing radius of the fusee compensates for that loss, helping the gear train receive a steadier supply. I like how understandable the idea becomes once you follow the path of the chain. 

There is a direct relationship between the shape of the cone and the problem it is there to solve, even if making the mechanism at this scale is anything but straightforward.

Aesthetically, the PLM has the restraint that draws me to early Lange. The silvered dial, blued hands, and 38.5 mm case give the yellow gold version a formality I find very appealing. 

Even the opening for the tourbillon feels properly considered within the layout. There is enough happening to keep your attention, but I never feel that the watch has been designed around the need to impress someone across the table.

The original series was limited to 200 pieces, so rarity is certainly part of its appeal. What matters more to me is its place in the collection presented in 1994. Looking at it now, with decades of Lange watches to compare it with, you can see how much of the company’s character was already there: the proportions, the finishing, and the willingness to attempt something mechanically demanding. 

That gives the first PLM an interest that survives each subsequent complication the company introduces.

I would still like to find a platinum example for myself. The quietness of the white metal suits what I like about the watch, and the size remains very reasonable for everything inside it.

Lange PLM in various materials and dial finishes

2. F.P. Journe: Order Within Randomness

The tourbillon is a good place to start with F.P. Journe. His first wristwatch prototype already combined a tourbillon with a remontoire, and when he introduced his own collection in 1999, the Tourbillon Souverain was at its center. 

 F.P. Journe's first watch, 1991

The layout, with the tourbillon on the left and the time on the right, has become so familiar that it is easy to look past the thinking behind it. The remontoire deserves just as much attention as the rotating cage beside it.

Journe was working on the same problem we saw with Lange: a mainspring delivers more torque when fully wound than it does as it runs down. Lange addresses that variation by changing the leverage between the barrel and the gear train. Journe introduces a small auxiliary spring further along the energy path, which supplies the escapement between regular recharges from the mainspring. This is the remontoire.

 Tourbillon Souverain's remontoire

Think of it as a small water reservoir fed by a much larger one. The pressure in the main reservoir can change, while the smaller reservoir is repeatedly refilled to a similar level. In the Journe, the gear train recharges the auxiliary spring once a second, and that spring supplies energy to the escapement until the next recharge. 

The mainspring still loses torque as it unwinds, but within the mechanism’s working range, the escapement receives a more consistent supply.

 Tourbillon Nouveau's remontoire

With the second-generation Tourbillon Nouveau, that one-second cycle also drives the jumping seconds display. I particularly like this detail because it gives you something to watch beyond the tourbillon itself. The seconds hand advances, the remontoire recharges, and a piece of the movement’s otherwise hidden activity becomes visible on the dial.

That makes the two mother-of-pearl examples especially interesting. So much of the movement is concerned with controlling variation, yet the dial changes with every movement of the wrist. Mother-of-pearl can look almost flat in one photograph and full of color in the next. Each piece has its own pattern, and even a good catalogue image can only show one version of what you might see in person.

 The Tourbillon Souverain with a MOP dial—a special edition marking Sincere's 50th anniversary

The rose gold example, made around 2005 for Singaporean retailer Sincere’s 50th anniversary, is one of just five pieces and has a black mother-of-pearl dial. “Black” is a fairly modest description of a material that can reveal several colors as the light moves across it. Against the warmth of the case, it gives the Tourbillon Nouveau a richness that brings it closer to jewelry than many collectors might expect from this movement.

 The Tourbillon Souverain with a MOP dial in platinum

The platinum example, made around 2006 for the same retailer in an edition of 15, has a dark mother-of-pearl dial. In the photographs, it catches flashes of blue and green. The platinum gives it a cooler appearance, and the result feels quite different from the rose gold watch, despite the familiar architecture underneath. I would want to see both in the same light before deciding which I preferred.

Five pieces and fifteen pieces will naturally attract attention. What holds my interest is how much these dials change a watch I already know. The Tourbillon Nouveau has a very distinct identity, and neither example loses it. 

You still have the asymmetric layout, the exposed mechanism, and the jumping seconds, but the mother-of-pearl changes the way the whole thing feels. That is the appeal of a special edition for me: discovering a version that gives you a fresh reason to look at a familiar watch.

3. Oscillon: A Different Approach to the Same Problem

Oscillon takes a little more explaining. Its watch is called L’Instant de Vérité, or “The Moment of Truth,” a name that refers to the first winding of a completed watch. After the work of making and assembling its components, the balance finally starts moving and the hands begin to turn. There is something appealingly practical about that moment. However much thought has gone into the watch, it still has to run.

Oscillon founders Cyrano Devanthey and Dominique Buser

From the front, it looks fairly traditional. Turn it over and the balance is likely to be the first thing you notice. It has an hourglass, or bow-tie, shape, with opposing inertia adjustment screws used to regulate the rate. 

The watchmakers’ explanation is straightforward: the shape makes its motion easier to see. A circular balance looks much the same at different points in its oscillation; this one gives the eye a shape to follow.

Calibre of the “L’Instant de Vérité”

It is an enjoyable detail, though it is worth keeping its role separate from the watch’s approach to power delivery. The balance regulates the movement. Oscillon’s answer to the changing torque of the mainspring is a system called the Tensator, and it begins with a question that Lange and Journe address further downstream: can the spring itself deliver more consistent torque?

The Tensator uses a long spring that transfers between two barrels, forming a reversed S-shaped curve between them. During winding, the spring is transferred onto the other barrel and bent against its natural curvature. 

Oscillon's Tensator system

As it runs, it tries to return to its original shape, driving the output barrel in the process. The useful part is that successive lengths of the spring undergo a similar change in curvature. Within its intended operating range, this produces a relatively steady torque, rather than the more pronounced variation of a conventional mainspring as it unwinds.

That puts Oscillon in an interesting position alongside the other two watches. Lange compensates for the mainspring’s changing torque, and Journe gives the escapement a separate, regularly recharged source of energy. 

Oscillon changes how the energy is stored and released in the first place. It is a substantial mechanical idea inside a watch whose dial gives very little of it away.

The founders, Dominique Buser and Cyrano Devanthey, met while studying watchmaking in the early 1990s. Buser later worked on the Opus V project developed by Urwerk and Harry Winston, continuing at Urwerk as an engineer; Devanthey eventually joined him there. 

Harry Winston Opus V | Source: s song

Their experience with unconventional mechanisms was well established before Oscillon. What interests me about their own watch is the decision to make so much of it using traditional manual machines.

In their workshop, most metal components begin as rods and plates. Making the part is a substantial part of the work, before there is anything to finish or decorate. “Hand Made” appears directly on the dial, but the choice goes beyond the inscription: it affects how the watch is designed. 

Cyrano Devanthey and Dominique Buser in their workshop

A component has to be conceived with some understanding of the machine and the operations that will eventually produce it.

Devanthey has explained that they used CNC machines extensively at Urwerk and appreciated what the technology allowed them to do. For Oscillon, they chose a different working process. That background matters. 

These are engineers familiar with modern manufacturing, choosing to spend their time at manual machines. It makes me curious about the individual decisions involved: how a part is held, how a curve is cut, and how an idea is adjusted to something they can actually make at the bench.

The watch becomes more interesting with that context. The restrained dial, the unusual balance, and the Tensator belong to the same project, even if they do not immediately suggest one another. I like that you can approach it as a fairly quiet watch and gradually discover how much thought has gone into it. There is plenty to discuss without the case or dial having to explain everything on first inspection.

Seen together, these three watches offer a useful way to follow one problem through three different movements. Lange varies the leverage of the transmission with a fusee and chain. Journe feeds the escapement through a remontoire. 

Oscillon uses a different kind of spring arrangement to make the output more consistent at its source. Understanding those differences gives you a reason to look closely at things that might otherwise register simply as unusual complications.

It also changes what I find myself paying attention to. The chain in the Lange and the jumping seconds in the Journe become easier to appreciate when you understand the work they are doing. With the Oscillon, I would want to turn the watch over and spend some time following the spring between its two barrels. 

That is the connection between the three for me. Each rewards a closer look, and each gives you something specific to think about the next time you wind it.