About a week ago I found a photo from a forum member showing two watches on one doubled strap system - and since I just got a second Apple (now that iOS 2.2 supports multiple watch pairing with one phone), I went to work.
By the way? This is one fiddly, pain in the Keister, project...it took me three tries and 72 hours off and on to get the right length for the buckle pieces. The goal of having both watches sitting squarely and equidistant from each other is almost impossible to measure until you have one in your hand. Final dimensions for my 6 1/2 inch wrist? Both sides 24mm tapering to 18mm, Buckle pieces 27mm long, long pieces approx. 50-52mm long. Your mileage will naturally vary, but not by a whole lot. Mine will fit up to a 7.25" wrist, so only add a very small amount to the lengths.
Final result? Surprisingly comfortable, eliminates any fear of battery loss during a busy day, capable of recharging on the wrist by slipping the charger under the watch if I'm going to be in my comfy chair for 30 minutes or more reading, and with the second watch in power reserve it allows for 72 hours of standby. After I learned that I could charge the top watch without a lot of hassle? I placed the back-up watch into full "power off" mode - effectively keeping it as insurance. I do need to order a pair of black anodized lug converters for the Sport, but that's non emergency.
I expect a full charge in "power off" will hold for months, or all those new Apple devices I've bought off the store shelf wouldn't have come with 80-90% charge.
Since my phone is the massive iPhone 6S Plus with a battery life close to an iPad mini? I now have probably 3-4 days of simple use if I'm not using harsh battery draining apps before all devices MUST be charged.
Alligator backed by ostrich - lug side is JB Kwik Weld to retain the shape and tube on the 24mm width. The rest is glued with Loctite super glue ("Caution! Bonds skin instantly! - and leather is "skin")18mm at the buckle.
I still need to 'tweak' one of the keepers, but as it sits? I like it a lot!
Inspired by the double chronograph worn by the legendary film maker and pilot Paul Mantz.
Here's Paul Mantz -
Here's the picture I found here which inspired me -
And my version - *Note - that light colored line near the lower watch is just a bit of gator grain I didn't get the polish into.
For Summer, now that I know the lengths? I'm going to make a couple in 24 X 24 NATO/ZULU nylon using the "undertuck" single ring keeper style. Thoughts?