The thumb test is the fine art of pressing on the tube with your thumb to see if it’s inflated. During testing, I took a pressure reading out of curiosity, and to the touch, road tires feel fully inflated around 30 psi. How pathetically sad—30 psi!—when you’re probably trying to reach at least 60 psi on a mountain bike, 70 or more on a hybrid, and it only goes up from there.
Every person who considers themselves a cycling enthusiast should know how to do at least some basic bike repairs. This is not just to satisfy an unwritten standard of being a bikehead, but because it has a lot of practical implications as well. It can make the difference between dealing with a minor issue quickly on your own or waiting a couple of days for a busy mechanic to squeeze you in. Moreover, in the long run, doing the dirty work yourself will save you a lot of money.
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.