well, sometimes you might need to cut the chain just to get moving again, and a chain tool is very handy for that!

For instance... say that your SunTour Cyclone GT derailleur breaks the spring for the lower pivot, and that permits the chain to jump out of the pulley cage and get between the spokes and the freewheel. In fact, it jams in there so hard that the freewheel has to be removed in order to free it (resulting in the need to replace half of the drive side spokes). The jammed chain means that the wheel can't turn and the bike can't roll.




A chain tool would at least permit you to get rid of the section stuck behind the freewheel, and maybe configure the remaining chain as a single speed ... maybe.
At a minimum, it would allow the bike to be rolled instead of carried.

I don't know why I picked that day to forget to bring my tools.

Steve in Peoria