CHPTR_Δ MDP 40 mm now in 40mm

CHPTR_Δ MDP 40 mm: A New Proportion for a Signature Complication 

First introduced in 44 mm, the CHPTR_Δ has become one of BA111OD’s most distinctive expressions of independent watchmaking. Its unconventional hour display, driven by a hypocycloidal complication, gives time a different geometry. 

Now, that signature mechanism is introduced in a new 40 mm format, produced as a one-off series of just 30 pieces. 

A signature complication, now in 40 mm 

The new CHPTR_Δ MDP 40 mm retains the architecture and visual identity of the original 44 mm version while offering a more compact presence on the wrist. 

The objective was not to reinterpret the complication, but to preserve its character within new proportions. The result is a watch that remains immediately recognizable as CHPTR_Δ, while opening the design to those who prefer a smaller case size. 

The geometry behind the hour indication 

At the heart of CHPTR_Δ is a hypocycloidal mechanism that determines the path of the hour indication. 

The principle can be compared to the geometry of a Spirograph: the interaction of rotating elements generates a precise trajectory. In the CHPTR_Δ, this mechanical geometry guides the yellow hour indicator along its distinctive triangular path around the dial. 

Rather than using a conventional circular hour display, the complication transforms the passage of time into a continuously evolving geometric motion. 

This unusual way of displaying the hour is not simply a graphic effect. The trajectory is created mechanically by the complication itself. 

Developed in La Chaux-de-Fonds 

The hypocycloidal complication was developed at our movement development workshop in La Chaux-de-Fonds, where BA111OD develops and explores proprietary mechanical solutions. 

It is built on a Soprod M100 automatic base movement, combining a reliable Swiss automatic calibre with a complication developed specifically for CHPTR_Δ. 

The watch is then designed and assembled in Neuchâtel, bringing together two of the regions at the heart of Swiss watchmaking. 

A closer look at the architecture 

The triangular architecture is more than a visual signature. It echoes the trajectory of the hour indication itself, allowing the mechanics and the aesthetic identity of the watch to speak the same language. 

The sapphire crystal caseback provides another perspective on the movement, revealing the Soprod M100 calibre that powers the watch. 

One-off production of 30 pieces 

The CHPTR_Δ MDP 40 mm will be produced once, in a series of just 30 pieces.

It is not presented as a numbered limited edition, but as a one-off production intended to mark the introduction of the CHPTR_Δ complication in its new 40 mm proportions.

Exclusively for Club 11:10 

For Club 11:10 members, the CHPTR_Δ MDP 40 mm comes with an additional stainless steel bracelet, complimentary with purchase. 

Both the blue rubber strap and stainless steel bracelet are equipped with the Easy Clip system, allowing the watch to move easily between two different expressions. 

A different way of telling time 

With the CHPTR_Δ MDP 40 mm, one of BA111OD’s most recognizable complications enters a new chapter. 

More compact in proportion, but unchanged in principle, it continues to express our approach to watchmaking: distinctive mechanics, local expertise and an unconventional interpretation of traditional horology.