Hands On Review- Tag Heuer Carrera 1887 Jack Heuer Edition (ref. Car2c11)

TAG Heuer Mikrogirder: The Inside Story

Last Updated on June 22, 2019 by Calibre 11

Mikrogirder- a New Approach

The Mikrogirder movement is based on the in-house TAG Heuer Mikrograph movement, which you see below. The magic of this movement is the dual-chain approach: a separate escapement for the watch (top right, 28,800 beats per hour) and the chronograph (bottom right, 360,000 beats per hour).

Tag Heuer Mikrogirder: The Inside Story

The Mikrogirder movement still uses a dual-chain approach- but instead of two traditional escapements as per the Mikrograph and Mikrotimer, you only see one, which is used for time-keeping (28,800 bph).

Tag Heuer Mikrogirder: The Inside Story

Instead of a balance wheel and hairsrping, the regulation of the chronograph is achieved via three micro-beams, or girders. You can see the three beams in the window below.

Tag Heuer Mikrogirder: The Inside Story

Jean-Christophe Babin explained the concept with the help of the model below:

“So the new system is based on beams…micro-beams. We still have the escapement wheel [below in red], but instead of 20 teeth, we have about 40 teeth and an anchor [the open-mouthed “C”  in white below], which is not a traditional anchor, but is linked the Excitatory beam [White]. There are three beams: the Excitatory beam; the Coupling beam [black]; and the Oscillating beam” [Blue].

Tag Heuer Mikrogirder: The Inside Story

Adds Semon:

“The anchor has a very specific geometry without pallets, and is manufactured as a beam. If you accelerate the anchor wheel you transform the kinetic energy of the anchor wheel into potential energy in the beam. Now you need an oscillator- one that’s very accurate. It’s a small beam that is calculated to have the first harmonic (the lowest frequency) at 1000hz. To reach this harmonic you need to transmit a level of energy to reach the harmonic. There’s a small contact point between the anchor beam and the oscillating beam [the coupling beam].”

So, to summarise, the three beams have the following roles:

  • Excitatory beam: generates energy by transforming kinetic energy into potential energy
  • Coupling beam: transforms the potential energy to the oscillator
  • Oscillating beam: generates the right frequency

The Oscillating beam vibrates at an angle of only 5 degrees, allowing it to move very fast. The Mikrotimer oscillates at 28 degrees, while most watches oscillate at over 300 degrees.

The benefit of this approach is that it allows a frequency of greater than 600-700 hertz to be generated- in the case of the Mikrogider Concept, the movement produces 1,000 hertz, meaning 7.2 million beats per hour and accuracy to 5/ 10,000ths of a second, or 1/ 2,000th.

The other benefit is reduced wear and power consumption, as Jean-Christophe Babin explains:

The Mikrogirder consumes about half the energy of a traditional regulator at the same frequency- so, at 500hz the power reserve instead of being 4 minutes is 8 minutes. This is because you have fewer parts in motion, and about 20% fewer components, so there is less wear and less use of energy”.