All multi-tools are not created equal, but most with a plethora of features will get plenty of the jobs done. I personally like, and use often, the Lezyne RAP-21 LED tool, which will run you around $30. I like it because not only is it a high quality construction, but it has just about everything you’ll need, plus a sweet mini light. This will give you a chain breaker, spoke wrench, disc brake wedge, and all the most often used Allen keys and drivers. We’re talking a decent number of tools for 1/4 of what they would cost buying them separately.
First, carbon. You already know you don’t need it for your casual weekend pursuits, because you’re not counting ounces the way a professional road racer would. But to quote an article from Velonews, “Remember that professional athletes operate in an entirely different environment than the rest of us. They are all very close to each other in terms of fitness, and they are also all very close to being the absolute best a human being can be. In short, you’re much better off upgrading your legs and dropping body fat through proper training and diet.”
This is a very basic book and unnecessarily repetitive in sections. It does introduce the reader to the basic nomenclature of bicycles and this is helpful when conversing with others. Unfortunately the repetitive sections were not replaced with chapters on 3 Speed in hub gear drives, or coaster breaks, or a chapter on Adult Tricycles and Tandems and E-Bikes.
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.