Meet the BikeTag: a smart bike sensor that offers crash detection, auto tracking, and live tracking to keep cyclists out of trouble. It pairs with your smartphone to monitor for crashes and notify your friends and loved ones. It tracks your ride as soon as you start riding. It can also notify your followers when you begin or end a ride.
BikeTag is pretty easy to use and does not weigh a whole lot. The battery life lasts for over a year. You can pre-order yours here.