Balancier Convexe S²

The Balancier Convexe S² is Greubel Forsey at its most wearable: 41.5mm in titanium, with the inclined double-balance system that defines the brand's chronometric philosophy packed into a case you can actually put on at dinner. The S² designation marks the second generation of the concept, refining the geometry of the twin inclined balances to improve rate stability across the positions a watch sees on a living wrist. If you want to own a serious Greubel Forsey without committing to the larger, heavier complications, this is the one.

What it is

Greubel Forsey was founded in 2004 by Robert Greubel and Stephen Forsey with a single obsession: improving chronometric performance through inclined and double tourbillons. The Balancier line followed as a natural evolution, asking whether a well-executed free-sprung balance with optimized geometry could rival the tourbillon on accuracy while delivering a cleaner, more legible dial. The S² arrived in 2021, adding a second inclined balance wheel and refining the architecture from the original Balancier Convexe.

At 41.5mm it sits smaller than most of the brand's output, which runs large by design. The titanium construction keeps weight reasonable for a movement of this complexity and finishing level.

Buying notes

The S² commands a significant premium over the standard Balancier Convexe, and the price difference is not always reflected in secondary market liquidity. Greubel Forsey allocates tightly, so authorized dealer relationships matter more here than at most brands. The convex sapphire crystal is load-bearing to the aesthetic, and a scratch or crack is an expensive, specialist repair.

Titanium is durable but shows surface scratches more readily than polished steel or gold, and the case finishing on this reference is part of the value. Like all Greubel Forsey pieces, service intervals are long but service costs are not trivial: budget for factory or authorized service every 5 to 7 years.

Market read

New retail pricing for the S² sits in the mid six figures, and the secondary market has been firm given limited production. Unlike some complicated watches that depreciate sharply, Greubel Forsey pieces tend to hold value when they come with full provenance and box and papers. Condition is paramount: a case with heavy wear or a crystal with scratches will trade at a meaningful discount.

Buy the cleanest example you can find.

Service expectations

The GF Balancier Convexe caliber is entirely in-house, hand-finished to Geneva Seal standards, and serviced exclusively through Greubel Forsey or a small number of authorized independent watchmakers. Parts are not available outside official channels. Always verify that any pre-owned example has service records or request a pre-purchase inspection by an authorized technician before buying.