I have a ResQLink. It comes with me on climbs and backpacking trips into the Cascades. I don't think I've ever brought it on a bike ride. This is the thing where you hit the panic button and then wait for the cavalry to show up no matter where you are. You don't use it if there's any way to get yourself out of the situation, only when you need a full blown rescue.
I considered a SPOT and the superior InReach, but these devices both route emergency calls through a private company and several years ago people died waiting for a rescue that never came because that company dropped the ball. They seem to have improved their internal procedures but I personally can't trust them after a failure like that.