More than any other tool in the kit, a reliable lever makes changing a tire easier, especially if you have road bike tires, which are difficult to remove. However, throughout testing, levers seemed to be the one item more prone to failure and poor design than anything else. For example, I found a random orange lever floating around my basement and I threw it in the test pool for fun—it seemed solid enough … until I began prying at the rim of a tire. It bent directly in half, slowly and smoothly, like taffy, and then was boomerang shaped forevermore.
These are some great ideas, especially the simple ones like bringing a garbage bag. That’s something so easy and cheap that it’s easy to forget entirely, but as you say, it can make a huge difference in the right circumstances. It’s also good that you discuss some minor bike repairs. That’s another thing that can salvage or destroy your ride. You want to be as prepared as possible for the best possible experience.
Friction gear systems are a lot simpler to adjust, because the movement of the derailer cable can be modulated as you ride, every time you change the gear- they require less cycle maintenance. Modern index shifting systems are a little more complicated because each ‘click’ must release the exact right amount of cable to allow the derailer to move the correct distance to move the chain from one gear to another. Setting up and adjusting a derailer is not difficult and requires only basic tools, but there is a methodical procedure to follow.