I toured Europe for three months and brought more equipment than I needed, but I don't think it was dumb anyway. I had spare spokes and a freewheel removal tool in case my rear wheel needed rebuilding, which of course it didn't. I might not have brought those things if I didn't have the skill to build wheels.

If I were touring South America, I would ride 26" wheels and would bring a spare tire, spokes, spoke wrench, master link, a couple of spare tubes, a patch kit, a pump, brake pads, spare cables, and a cassette tool. This is not a complete list.