Stems
A crucial part of your controls, stems come in many different lengths and rises which affect your riding position. These days, most stems work with threadless headsets - meaning they clamp straight on to the fork's steerer tube and cannot be adjusted for height - though some still use the 'quill' method, allowing more adjustability, but with a weight penalty. Think about what you want, and bear in mind that a shorter stem means quicker steering, but a less efficient and aerodynamic position.
