Stems connect the steerer tube from the fork to the handlebars.

There are three common types of stems: 

• Quill stems
  
• Ahead
  
• Direct Mount

They can be changed to adjust your riding position and will vary in length, material, diameter, angle and some are adjustable. Ahead stems are the most common and can be found on most bikes. Direct-mount stems usually connect to double-crown forks and handlebars on downhill and freeride MTB's.