The Tourbillon Rétrograde Chronograph is the highest-priced watch in the new Da Vinci collection by IWC, and it includes three complications: tourbillon, chronograph and retrograde date. It is powered by the new in-house 89900 calibre, self-winding, running at 28,800 vibrations per hour, 4 Hertz. It has some significant technical features.
Advanced materials in the 89900 movement
The flying tourbillon at 6 o’clock has a stop-seconds function based on two levers that grip the balance ring. This allows the balance to be stopped when the crown is pulled out to the time-setting position. Another feature, visible through the circular tourbillon window, is the unusual escape wheel, with a design reminiscent of Leonardo da Vinci’s geometrical sketches, but that was in fact computer-generated for optimum strength and rigidity. The escape wheel and the pallet are in diamond-coated silicon, which is very hard and reduces friction. The 89900 calibre provides a 68-hour power reserve.
Column wheel, vertical clutch
At the top of the dial, the chronograph subdial shows both hours and minutes, so that the watch can time events of up to 12 hours. The chronograph seconds hand can be read off a scale marked in quarter seconds. The pushers enable the flyback function to be operated: pressing the pusher at 4 o’clock while the chronograph is running immediately resets and restarts the chronograph hands. IWC don’t specify what type of chronograph movement it is, but the chronographs in this 89000-calibre family have a column wheel and a vertical clutch, with separate clutches for the chronograph seconds hand and the hour and minute hands on the chronograph totalizer. The effect of a column wheel is smoother pusher operation; the vertical clutch reduces loss of movement amplitude when the chronograph is activated, improving precision. It also reduces wear, so that the chronograph can be left running continuously without any adverse effects.
The retrograde date display on the left is an unusual and attractive feature. It has to be adjusted for months with less than 31 days, and this is easy, with adjustment performed using the crown.
Case and strap
The watch is large, at 44 mm diameter and 17 mm thickness. The case is in red gold with dark brown alligator strap by Santoni, and a red gold folding clasp. Water resistance is 3 bars.
Price and reference
The watch is reference IW393101, and it costs €113,000, $103,000, 115,000 Swiss francs. Available later in 2017. More information from the IWC website.