Bike stems ensure the handlebars are secure; it may be an essential component but there is a choice in what bike stem you need. Stem type, material and length all play a role in how your bike handles, so choose carefully. There are bike stems for different types of bike. The most important consideration when buying a new bike stem is the length. A shorter stem may result in responsive handling; a mid-length stem provides a balance of responsiveness and efficiency. For a road bike, a long stem can help achieve that low, aerodynamic position.