IWC Grand Complication Question (?)

Hello All,

I'm relatively new to the IWC world as I have my first IWC on order and will receive it in the next few days (hopefully!)

Anyways, I have always had this Grand Complication question that I coudn't find any answers to on the Internet, which is:

Is it true that IWC uses a 7750 base for the GC? And if so, why? I love and respect IWC as a manufacture and they have always made wonderful movements here and there, i.e., 5000 sereis...etc.

Is there a reason to why they are using an ETA base for such a "grand" watch and not a fully in-house movement?

Thanks for this wonderful forum and I look forward to contributing in the future!

PS For those who are wondering, my incoming IWC is the 3714-01

Yes. The Grande Complication is a wonder feat of watchmaking. I think the reason why you see this base movement in the Grande Complication is it has been proven to be very robust, and it has proven to be durable and reliable.

Of course MOST of the Grande Complication's Calibre 79091 movement is actually in-house. Not only is the base completely rebuilt, re-finished and enhanced by IWC - you also have a number of other IWC-proprietary modules built on top of it, such as:

Minute Repeating Module:

Perpetual Calendar Module:

If you put it this way the risk is to lose a correct perspective. When GC came out it was considered relatively in the forefront for those times. At the time GC was projected there was not such a wide choice of calibers, IWC never had a chrono caliber of its own, the first was the recent 89360, cal 7750 was considered the natural choice, being a reliable base to develop and support the complexity of the whole movement.

It was also a consistant choice in terms of production, being that caliber hosted by several other models IWC was producing, not considering the caliber was very familiar to IWC watchmakers, with benefit to the whole production process.

I don't like the crhonograph cam, I'd much have preferred a column wheel but, at the same time, I can't do anything but admire the modules Richard posted above, they came out from the creative minds of two of the most brilliant watchmakers of the period between last and current century, Kurt Klaus and Giulio Papi.

It's a very expensive watch but it still costs what, a third of the price of similar watches with definitely worse technical solution? I'm specifically thinking of some of the models first seen at Baselworld 2011.