First Look at the Sartory-Billard SB10 Jumping Hour – Disco Ball and Black Sapphire
Jump Hours That Don't Tell Time, But Instead Perform It
The SB10, unveiled for the brand's tenth anniversary, is a direct descendant of the SB08 — a multi-sapphire, remontoir d'égalité tourbillon concept from 2024 that would have required north of one million euros to develop. That watch was never going to happen. But its core idea — a wide jumping hour aperture, a fluid minute display, and a central surface completely freed from the constraints of a traditional dial — stuck with founder Armand Billard. The SB10 is that idea stripped to its essentials and made real.
It launches in two versions: the Disco Ball and the Black Sapphire. Both share the same case, movement, and display architecture. The difference is the cabochon — and that difference changes everything about how each watch feels on the wrist.
The Concept: No Dial, No Hands
Let's start with what's missing, because that's the point.
The SB10 has no dial. No hands. Time is displayed entirely through two sapphire discs, each roughly 0.2 mm thick, that are essentially invisible unless you know where to look. The hour disc sits beneath a large aperture at six o'clock and jumps 30 degrees every 60 minutes — a sharp, instantaneous snap that reveals the next numeral. The minute disc rotates continuously around the cabochon, with a peripheral Super-LumiNova BGW9 ring and a red marker indicating the current minute.
Two rhythms coexist: the punctual jump of the hour and the slow, continuous orbit of the minutes. It's a fundamentally different way of reading time, and Sartory-Billard has leaned all the way into it.
The hour numerals deserve their own mention. They were drawn specifically for this watch by typographer Simon Schmidt, and they're big — nearly twice the size you'd see on most jumping hour watches. Billard is characteristically blunt about why: "I'm 50 years old — I need to see the time clearly." The result is a jumping hour display that's actually legible at a glance, which is rarer than it should be in this category.
The Cabochon
Where a dial would normally sit, the SB10 has a cabochon — a polished, sculpted surface mounted externally like a gemstone. It has no mechanical function. It exists to give the watch a material center of gravity, something to look at and, critically, something to touch.
This is not interchangeable. It's fixed to the watch at purchase, which is a deliberate choice. Sartory-Billard wants each SB10 to feel like a singular object rather than a modular platform. Beyond the two launch editions, the brand is offering fully bespoke cabochons — natural stone, meteorite, engraving, gem-setting — turning the SB10 into a canvas for individual expression.
Disco Ball
The Disco Ball version features a steel cabochon with a surface composed of hundreds of micro-facets. The press materials call it guilloché, though "engine-turned faceting" might be more precise — this isn't fine engraved line work in the classical sense. It's a geometric pattern designed to fragment and scatter light from every angle.
The effect is kinetic. Every movement of the wrist reshuffles the reflections across the surface. It's also tactile — you can feel the faceted texture under your fingertips, which is unusual and surprisingly compelling for a watch you'd normally just look at. The name is apt. This is the extroverted SB10.
Black Sapphire
The Black Sapphire takes the opposite approach. Its cabochon is smoked sapphire — dark, translucent, and moody. Through it, you get a veiled view of the watch's mechanical architecture: the jumping hour disc, the module, Schmidt's typography. Depending on the angle and the light, the sapphire shifts between translucent, opaque, and reflective. It reveals without fully exposing.
At night, the contrast becomes dramatic. The Super-LumiNova minute ring charges during the day and glows turquoise in the dark — a floating halo suspended around a near-black center. Where the Disco Ball performs in daylight, the Black Sapphire comes alive after dark.
Movement
Inside is the La Joux-Perret G100 — an automatic calibre with a 55-hour power reserve, paired with a patented jumping hour module. It's a pragmatic choice. LJP supplies proven, reliable movements, and Sartory-Billard has focused its engineering effort on the jumping hour complication and the sapphire disc integration rather than reinventing the base movement. The jump is reportedly crisp and precise, which matters — a sluggish jumping hour ruins the entire experience.
The brand does have its own movement development arm, Horocraft, based in Switzerland. But for the SB10, the priority was clearly accessibility and reliability over in-house bragging rights. That's the right call for a watch at this price point.
Case & Wearability
The SB10 sits in a 39.5 mm 316L stainless steel case with alternating polished and brushed surfaces. It measures 11.5 mm thick with a 44 mm lug-to-lug — compact, balanced proportions that should wear well on a wide range of wrists. Water resistance is 80 meters, and there's an open caseback.
Two bracelet options are available: a rubber strap offered in seven colors (white, grey, black, blue, red, brown, green) or a stainless steel bracelet with alternating brushed and polished links. Both feature quick-release pins for easy swaps.
Final Thoughts
The SB10 is the kind of watch that makes you pay attention to a brand you may have only been loosely tracking. Sartory-Billard has been doing interesting dial work for a decade, but this feels like a step change — not just in ambition, but in clarity of vision. The cabochon concept is a genuine idea, not a gimmick. The jumping hour execution is thoughtful. The price-to-substance ratio is hard to argue with.
The real question is which version to choose. The Disco Ball is immediate and physical — light and texture hitting you the moment you look at it. The Black Sapphire is slower, deeper, more about what you discover over time. Both are unmistakably the same watch, and both feel completely different on the wrist.
Pricing & Availability
Pricing is $4,500 (on rubber). For a jumping hour complication with sapphire discs, custom typography, a patented module, and this level of design ambition from an established independent, that's aggressive.
Production is limited to 300 individually numbered pieces for 2026, with first deliveries starting in May. Both the Disco Ball and Black Sapphire are available now at collectivehorology.com.
As always, thanks for reading and supporting independent watchmaking.