The Grinder® The most efficient winding technology ever
For more than a century, automatic winding has been treated as a problem already solved. The principle had settled into something simple: as the wearer moves, a half-circle rotor swings and winds the mainspring. Refinements followed. Bearings improved, friction dropped, and bidirectional winding systems appeared. But the core architecture changed very little. Not because nobody could improve it. Because for more than a century, nobody had a reason to question it. Until the Freak. When Ulysse Nardin set out to create an automatic version of its most radical watch, it discovered something the industry had quietly accepted for generations: conventional automatic winding wastes a surprising amount of energy. For most watches, that inefficiency doesn't matter. For the Freak, it changed everything.
A watch that challenged automatic winding itself
When it was launched in 2001, the Freak rewrote the rules of watchmaking.
Its revolutionary architecture replaced traditional hands with the movement itself. Every hour, the entire mechanism rotates around the dial as part of the display. A giant mainspring stretching nearly two metres delivered seven days of power reserve and was wound manually through the caseback. It was a mechanical manifesto. But it also created a challenge no conventional automatic watch had ever faced.
Years later, when Ulysse Nardin explored the idea of an automatic Freak, its engineers quickly discovered that traditional self-winding systems were not designed for a watch like this. Because the movement itself displays the time, with the entire carousel rotating once every hour, the Freak requires significantly more energy than a conventional watch. The challenge was suddenly clear: it was not the Freak that needed to adapt. It was automatic winding.
A limitation hidden in plain sight
The limitation was not unique to the Freak. It had been present in automatic watches for decades.
A standard automatic watch works through a simple chain of motion. As the rotor turns, pawls engage a winding wheel and advance it step by step. The limitation lies in engagement: the rotor must travel far enough for the next tooth to be caught. In practice, not every movement of the wrist becomes stored energy. Short reversals and partial wrist movements are often lost before they ever reach the mainspring. For generations, this inefficiency was accepted because conventional watches required relatively little energy, and traditional winding systems provided enough to keep them running.
The Freak exposed that limitation. Suddenly, every movement counted. A weakness long hidden in plain sight became impossible to ignore. The answer was not a better rotor. It was a completely different approach to automatic winding.
To make the Freak automatic, Ulysse Nardin's engineers had to rethink how energy is captured, transferred and preserved—not as an incremental improvement, but as a new architecture.
The result was the Grinder®.
Reinventing automatic winding
Introduced in 2017 with the Freak InnoVision 2 concept watch, the Grinder became one of the most significant rethinks of automatic winding in modern watchmaking. Designed to capture more energy from every movement of the wrist, it addressed one of the last hidden constraints of automatic winding. For the first time, Ulysse Nardin could make the Freak automatic without compromising the architecture that had made it revolutionary in the first place.
DiscoverIt did not simply improve automatic winding. It made the automatic Freak possible. Most watchmakers would have tried to optimise the existing solution. Ulysse Nardin chose a different path. Instead of asking how to improve a traditional winding system, its engineers asked a more fundamental question: How much of the wearer's motion is actually being wasted? The Grinder was designed to recover as much of that lost energy as possible.
At first glance, the difference is already visible. Instead of a traditional oscillating weight, the Grinder uses a peripheral rotor that increases mass by approximately 50 percent. More mass means greater inertia. Even small wrist movements generate a stronger mechanical impulse, allowing the system to react more efficiently to everyday motion. But the real breakthrough lies beneath.
Closing the gap in energy capture
In a conventional system, two ratchets transfer energy from the rotor to the mainspring. Because the spacing between engagements is relatively wide, small wrist movements often fail to generate useful winding. The Grinder dramatically reduces those losses. Using four spring-loaded ratchets instead of two, it multiplies engagement opportunities and captures energy from much smaller movements. Less travel is required before useful winding begins.
Imagine riding a bicycle with only two opportunities per revolution to apply power. Between those points, momentum alone keeps the system moving. Now imagine multiplying those engagement points. Power is delivered more frequently, less effort is wasted and efficiency increases. The Grinder follows the same principle, multiplying engagement opportunities to recover energy from even the smallest wrist movements. Not by generating more energy. By wasting significantly less of it.
Inspired by the sea
The name "Grinder" comes from competitive sailing, where sailors, working in pairs, operate the winches known as "coffee grinders". Their role is simple: transform every movement into a continuous flow of usable power with as little loss as possible. The Grinder applies this principle. With four spring-loaded arms working in sequence instead of two, it creates a more continuous transfer of energy and dramatically reduces the gaps between useful inputs.
Like its nautical namesake, it is designed not to generate more energy, but to capture more of the energy already available.
Twice the efficiency
The Grinder's performance does not come from a single invention. A heavier rotor improves inertial response. A four-point ratchet system reduces dead travel and captures more motion. A compliant flexure architecture helps recover energy from multiple directions while minimising losses.
Together, these innovations allow the Grinder to achieve up to twice the winding efficiency of conventional automatic systems. In an industry where progress is often measured in fractions, doubling efficiency is not an optimisation. It is a change of category.
That breakthrough paved the way for every automatic Freak that followed. From the Freak Vision to the Freak S, Freak ONE, UR-Freak and Super Freak, the Grinder became the foundation of the collection's automatic architecture. What began as a solution to a unique challenge became something much larger: a platform for future innovation.
More than a winding system
For generations, watchmakers focused on improving automatic winding. Ulysse Nardin questioned it.
The Grinder was born from a challenge no conventional watch had ever presented. Solving that challenge required more than optimisation. It required a new way of thinking about how mechanical energy is captured and transmitted.
By recovering up to twice as much energy from wrist motion, the Grinder made the automatic Freak possible without compromising the architecture that made the watch unique.
It fundamentally redefined how energy could be captured in a mechanical self-winding watch.
Protected by multiple patents, the Grinder reflects a philosophy that has guided Ulysse Nardin for generations: pushing the limits of mechanical watchmaking through innovation.