Dropper posts are a no-brainer for all mountain and trail bikes

Perfect for gravity focussed riders looking for durable shorts that are cut below the knees

Adjustable to fit a variety of MTB frames with flat and sloping top tubes

so grab one of these and you'll be able to run your thru-axle or QR bike with the S1

Shimano EW-SD50 eBike Electric Di2 Wire - Black - 1400mm eBay Dropper posts are a no-brainerThe SD50 E TUBE wire transmits interactive signals and provides power to E TUBE DI2 drivetrains. It has a compact, waterproof connector and can be easily routed internally in handlebars and frames thanks to its "plug & gap" connection. Available in various lengths. Application: Provides power and interactive signals to E TUBE DI2 drivetrains. Compatibility: E TUBE system Not compatible with Dura Ace 7970 Di2 wiring. E tube connector (QTY): 2 E tube