Complication · Precision
Inclined Tourbillon
Partially verifiedA tourbillon where the balance is set at an angle (usually 25 or 30 degrees) to the movement.
Definition
A tourbillon where the balance is set at an angle (usually 25 or 30 degrees) to the movement.
Historical origin
Developed by Greubel Forsey to improve chronometric performance by avoiding the most extreme gravitational positions.
How it works
The entire tourbillon cage is tilted relative to the mainplate.
The angle ensures that the balance never sits perfectly flat or perfectly vertical in common wrist positions.
Pocket watch context
None.
Wristwatch context
A signature complication of Greubel Forsey.
Identification
- Tilted balance wheel visible through the dial or caseback
Servicing notes
Requires specialist training and tooling.
General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.
Related photographs
No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.
Sources & references
- de Carle, D., Watch and Clock Encyclopedia
- Britten, F. J., Old Clocks and Watches and Their Makers
- Horological Journal (British Horological Institute), technical articles
Where sources disagree, the disagreement is stated rather than resolved silently.