@gcvsa asked a while back:
Q2. What tools would you personally recommend cyclists carry on-bike? Not types of tools, but specific models, with context (type of ride or rider).
I will start with the Wiha 66994 ball-end long hex wrenches. It's a 9-piece set, but I only carry the 3, 4, 5, and 6 mm wrenches for local, in-town rides. I find these are more effective and usually lighter than fold-up multi-tool types, and are the tools I most often need for adjustments.