The Speake-Marin Bi-Tourbillon features two 60-second tourbillons connected by a spring clutch system, with a power-reserve indicator and a day/night indicator above and below the grand feu enamel dial. Emphasising this technical tour de force, the two tourbillons are vertically aligned on the left side, ensuring sufficient space to clearly distinguish the dial. Each tourbillon has its own gear-train and is powered by its own mainspring barrel, both of which are simultaneously wound via the crown. A miniature limited-slip spring gearbox known as an équilibreur de marche (rate equalizer) - the spring absorbs and balances any subtle variations between the two cages - links the two tourbillon regulators.
One & Two