Phillips head screwdriver
Phillips head screwdriver
Used primarily for adjusting limit screws on derailleurs, the Phillips head screwdriver is, again, is unlikely to be called into action on a regular basis.
Limit screws are something that should have been set way before you think about getting on the bike and riding but, like a number of things on this list, could conceivably need to be adjusted mid-ride. Plus, this one extra tool will add an almost imperceptible amount of weight to your multi-tool, so it’s definitely worth having it with you.