It's a simple tradeoff, risk/reward analysis or roll of the dice decision. I don't carry a chain tool. However I can call an Uber because I do carry my cell phone. I could carry a chain tool, and have that sitting in my pocket for years and years of rides, going unused but for the unlikely eventuality, but choose not to. Aside from flat tire parts/tools, this tool has sufficed for years of day-riding. Other tools I don't carry = 8mm (pedal) hex, bearing extractor, pliers, wheel truing stand, peening tool, torque wrench, etc. If I toured, I'd probably do something different.
