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IWC 7900

The 790 (and derivatives 7900, 79000, and 75000) family of calibres is a series of midrange automatic chronograph movements produced by IWC but based on the Valjoux 7750 series.

Details

The Valjoux 7750 movement was extremely important to the resurgence of IWC and the basic design remains in use today. The company has used it for many important innovations since the 1980's, including the perpetual calendar module developed by Kurt Klaus in 1985. IWC also used the 7750 base for their first grande complications: The 1991 Cal. 79091 (which remains in production) and 1992 Cal. 18680Il Destriero Scafusia”. Other key innovations are the Habring Cal. 79030 Doppelchronograph of 1991 and Cal. 76061 tourbillon of 1999.

The first IWC version of the basic Valjoux 7750 movement was the Cal. 790, dating to 1981. This was used in the Porsche Design watches built by IWC through 1988 and was essentially stock apart from nickel plating. It lent its name to most movements that followed, with the “79” prefix denoting a 7750 base even today. This was the base upon which Kurt Klaus designed his Cal. 7906, which re-established IWC in the Swiss watch industry. This movement was extremely innovative, using fewer components than previous modules, and was the key component in the 1985 IWC Da Vinci Perpetual Calendar, a watch that remained in production for more than 30 years.

In the 1990s, IWC used the 7750 as a base for their grande complication and tourbillon movements. In 1990, IWC announced their first grande complication: Cal. 79091 used the 7750 base, adding a minute repeater to the Klaus perpetual calendar module. The Grande Complication, Ref. 3770 remains in production to this day.

IWC Pilot's Watch Doppelchronograph
with IWC 79230 (ETA 7750 base)
© IWC

Another important chronograph advancement came in 1991 with the addition of an affordable rattrapante mechanism designed by Richard Habring. Cal. 79030 was the first mass-produced split-seconds mechanism, and it was as robust and easy to use as Klaus' perpetual calendar. This movement was the basis for the IWC Pilot's Watch Doppelchronograph and remains in production today as Cal. 79420. The perpetual calendar and rattrapante are combined in the 1995 Cal. 79251.

In 1992, IWC added a tourbillon and Richard Habring's rattrapante mechanism to the grande complication, resulting in the famous “Il Destriero Scafusia”. A simpler tourbillon movement followed in 1999, Cal. 76061.

Many of these movements are hand winding and include modifications to the basic plates of the 7750 base. In 1995, IWC further modified the donor movement, moving the small seconds to 6 00 and replacing much of the movement in the process. Cal. 76240 is the hand winding rattrapante version of this movement, while Cal. 79240 is the automatic. The latter movement remains in production as Cal. 79350 as of 2019.

The final novel complication on the 7750 base was Cal. 79470. Introduced in 2004, this movement includes a novel split minutes feature on the running minutes hand.

In the 2010's, IWC began moving away from ETA as a component supplier, gradually replacing the IWC 79320 (based on the ETA 7750) with the IWC 75320 (based on the very similar Sellita SW300-1).

In 2010, IWC introduced an in-house flyback chronograph movement, the Cal. 89000 family and used this instead of the rattrapante in some models. However, this movement proved too costly for the market and the rattrapante Cal. 79420 used instead. Starting in 2016, IWC is replacing Cal. 75320 with their manufacture IWC 69000 family, which although based on the 7750 architecture, is constructed in-house. This movement is also displacing Cal. 79350 in new models. It is likely that the Cal. 790 family will be phased out entirely in the coming years.

Movement family

iwc_7900.txt · Last modified: 24.11.2021 09:28 by gerdlothar

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