How can I convert a single-speed bike to a three-speed bike?

To convert a single-speed bike to a three-speed bike, you will need to replace the rear wheel with a wheel that has a built-in internal gear hub. This hub will allow you to shift between three different gears, giving you more versatility in your riding. Additionally, you may need to install a new shifter and cable to control the gears. It is recommended to consult a professional bike mechanic for assistance with this conversion.