This short manual is intended for fully installed drivetrains. Hence the inner wire is already under tension and can be adjusted using the barrel adjuster at the gear shifter. Please turn the barrel until it is half-way screwed in. This way you can later use it properly to adjust the inner wire tension.
There are other factors that determine whether your drivetrain will perform gear changes smoothly. A bent derailleur hanger, wear and tear on cable housings, inner wires, derailleur, cassette and chain can make adjustments impossible. We will show you in a later post how to check for worn components that need replacement.
We worked with a new Shimano rear derailleur in this post. Other models and brands may vary in design and layout of the screws. However, their labelling and function is essentially the same.