iPhone 7 Smart Battery Case bike handlebar mount with GoPro mount

Attach an iPhone7 with [Apple's Smart Battery Case](https://www.apple.com/shop/product/MN002LL/A/iphone-7-smart-battery-case-black) to your bike's handlebars (31.8mm / 1.25 inch). Includes a GoPro mount underneath.

Blog post describing usage of case, recommended phone apps and config, and alternatives tested while developing this mount:
https://jeffstreet.bike/post/181173517321/phone-as-cycling-computer-mount-the-idea-is-to