Proper Shifting Helps Your Bike Last Longer, Work Better - With so many gears on a multi-speed bike, it's tempting to use them all. Yet, a derailleur-equipped bicycle actually has a few gears you're better off not using, based upon how extreme the sideways bend in the chain can become. "Chainline" is the term which refers to the relative straightness of the chain's path as it encircles the front and rear gears. Chainline is at its most problematic angle when using two combinations of gears together: either the largest gears in front and back, or the smallest gears in front and back. Even when your drivetrain (derailleurs, gearsets, and chain) is properly set up and adjusted, using these "extreme" gear combinations creates excessive drivetrain noise and wear, which reduces the useful life of the drivetrain parts. You can still celebrate that your bike has 24 speeds. And if you only use 22 of them, it'll last you longer, too.