It is fashionable these days for a company to have a Mission Statement. Here's ours:

The Mission of GearTrains is to provide its principal the intellectual pleasure of devising highly accurate gear trains for representing astronomical or other phenomena for horological purposes and the opportunity to work with and visit interesting people, skilled watch and clock designers and makers, and the interesting places where they work.


What we do:

  • Determine appropriate overall (reduction) ratios for representing astronomical phenomena based on the principal's astronomical experience and understanding of time.
  • Devise gear trains which best satisfy tradeoffs among clock and watch designers' constraints of tooth counts, number of intermediate shafts, size and configuration of space available for a gear train, and gear train accuracy. Gear train example
  • Assist watch and clock restorers in determining tooth counts when multiple gears are missing in a watch or clock. Missing gears example
  • Assist in solving similar gear train problems in non-horological settings.

  • For inquiries, please email us at:, or

    Write us at:

    Attn: John G. Kirk
    325 Palisades Drive
    Santa Barbara, CA 93109
    U. S. A.

    Background: Watch No. 1734 by Abraham-Louis Breguet, ca. 1807.