IWC 50900

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Cal. 50900 is an oversized in-house eight day tourbillon movement in the Cal. 50000 family produced by IWC since 2010.


On its release in 2000 in the limited-edition IWC Portugieser 2000, IWC's Cal. 5000 was lauded by the brand's followers. It marked the restart of completely-in-house watch movement development for the company and brought back the legendary Pellaton winding system. The movement was seen as a landmark in other ways, with 8-day power reserve, automatic winding, and a massive 16.75 ligne (38.2 mm) diameter.

In 2004, IWC introduced the Portugieser Tourbillon Mystère, Ref. 5042 with a new version of the Cal. 5000. The new Cal. 50900 adds a tourbillon and retrograde power reserve indicator to the movement family. The tourbillon is visible through an opening in the dial at 12:00, while the retrograde power reserve needle sits at 4:30. Running small seconds are placed at 9:00.

In 2010, IWC introduced the Portugieser Tourbillon Mystère Rétrograde, Ref. 5044 with a new version of the Cal. 50900. The new Cal. 51900 adds a retrograde date by pointer at 7:30 to the movement. The power reserve indicator is also retrograde and is moved back to 3:00.

Cal. 51900 was updated in 2017 with a perpetual calendar module to become Cal. 51950. This was used in the limited-edition Portugieser Perpetual Calendar Tourbillon "150 Years", Ref. 5045.



Automatic movement
Bi-directional winding (Pellaton winding system) on spring-mounted rotor, cam disc, ruby wheels and 2 latches on ratchet wheel, gear reduction: 175:1
Escapement: stone lever
Yoke winding system
Breguet hairspring
Incabloc shock protection
Two-armed screw balance with 16 weight srews and 2 adjustment eccentrics on the escapement arms
Hairspring Nivarox 1 with Breguet bending
IWC precision adjustment: hairspring stud and regulator adjustable with eccentric
Bridges and plate nickel coated, engravings gilded, decoration of type "Côtes circulaires"
Weight segment IWC-style (without gold medaillon) with gilded Probus-Scafusia engraving, plate wheel, crown wheels, ratchet, barrel lid and differential gear with solar grinding


Hours, minutes
Tourbillon at 12:00
Retrograde power reserve indicator at 4:30
Small seconds at 9:00
Retrograde power reserve indicator at 3:00
Retrograde date by pointer at 7:30


16,75 lignes
Ø 38.2 mm
Height 8.9 mm
44 jewels
19,800 A/h
Power reserve 204 h, limited to 168 h

Production period:

Production: 2004-Present

See Also