IWC XS Strap sizing question for 3717 Pilot

I own the IWC 3717 Pilot watch and want to pair it with a dark brown leather strap. My wrist measures 6+ inches around so I need a short strap. I also want a deployment clasp because I will be taking off the watch off frequently.

There are two straps that I fancy. The first picture shows my ideal strap (pictured on my IWC 3717). It is the strap from the Big Pilot. Dark brown leather, off white stitching, rivets and a deployment clasp. The strap measures 22mm wide and 190mm overall in length (135x55mm). The strap is too long for my wrist. The strap starting from the 6:00 position runs all the way to the 12:00 position when worn to the correct “tightness” on my wrist. The AD claims this is the XS size for a Big Pilot. I was under the impression the XS overall strap length was closer to 170mm for deployment buckle straps.
I also feel the deployment clasp pushing into my wrist. Will the leather break in overtime and be less of an irritant?

The next picture shows the 21mm St. Exupery dark brown buffalo ref. 21700 sized XS. I am not sure if the strap is pin/tang specific or deployment clasp specific. I get the sense it is the former. Does the strap come in a deployment specific design? I think the measurement was 170mm overall (105x65mm). I am not sure of that (apologies). What are the overall lengths of the XS deployment style? What about the lengths at the 12:00 positions and 6:00 positions? Is the deployment clasp a smaller size for the 21mm Saint Expery than for the 22mm Big Pilot strap?

I am sure some of you are wondering why I don’t just inquire with my AD. They have been a bit slow in responding and I get the sense they want to sell me straps they have in stock. Other than that they have been fantastic.

Some of you may be wondering why I am cramming a 22mm strap into a 21mm space – I am in love with the strap with the rivets (first picture). Which brings me to the 3rd picture – it seems someone has put a black strap with rivets onto the 3717. Does that strap also come in dark brown buffalo leather? Is that indeed a 21mm strap?

Andy Stevens : I wanted to ask these questions outside of your thread. Thanks so much for your advice.

Thanks for your help guys.

Well, I have a 7" wrist and my BP has the regular length 55/140mm strap.

Notice how far the 'tail' runs up when I am wearing it on the 3rd hole.

I switch the strap orientation to have the long end at 6 and the short end at 12. This seems to help prevent the watch from sitting towards the edge of my wrist, and seems to keep it center on my wrist.

I'm not really sure of the short strap measurement but I hope this gives you a visual idea. I hope this helps, even a little.

Hi G, welcome to the forum,

have to run off in a while so this is a little hasty attempt to answer your questions. my opinion only, and because I don't have the precise models you have, the strap sizes I have used are taken from straps from hat I believe to be the similar casing designs as the models u have mentioned.

a) you mentioned your first pic shows the strap fo the Big Pilot - would this be the ref 5004 ? This is the XS Big Pilot crocodile straps - a blue one that was given to me complimentary by the boutique:

It measures 135mm-55mm.

I am also informed that very recently, there is a XXS Big Pilot strap in black -- even shorter than the XS strap. I don't have the dimensions, but I am due to get one soon.

b) 105-65mm will be the pin buckle XS strap for the ref 3717 (which is the same case design as your St Ex) -- i am inferring here, because this is the additional leather pin buckle strap given to me when I purchased the Patrouille Suisse 3717-14:

The XS size for deployant should be: 125mm-45mm (there is a bit of ambiguity for me in this - as not all my straps conform exactly to this measurement, perhaps some due to wear and tear)

The standard IWC deployant clasp should measure 18mm at the deployant end - I think your deployant will fit all/most IWC OEM straps - including the older models.

c) as to whether IWC has brown buffalo with rivets - I think you will have to look at the older models. I'm not a fan of buffalo, so I have not kept a keen eye on this topic - other forummers would have a better idea. Rivets/studs are conspicuously missing in this year's collection (not something good nor bad, imo), except in the 2012 Father and Son:

As a final note, because of my smaller wrist I have had to customize all of my pilot straps - the exceptions being the XXS one I am a getting, and the stamped leather ones for the DFB Big Pilot (which I think is amazing). If you want more information in this regard, you are more than welcome to email me.

hope this helps, and sorry if it added to the confusion !