How to Choose the Length of a Stem
3 Answers
If you want an aggressive and aerodynamic posture, a longer stem will stretch your back muscles, creating a more leaned-over riding position. For a comfortable setup, a shorter stem length is more suitable. The stem length must be considered as a comprehensive factor along with the frame size, saddle height, saddle fore-aft position, and the shape and size of the handlebars.
When choosing the stem length, I prefer to first consider riding comfort and my own body characteristics. Having ridden bicycles for over a decade, I've found that a stem that's too long increases pressure on the wrists and back, while one that's too short makes the bike unstable and prone to tipping. The normal range is between 70 to 120 millimeters, but don't just pick randomly. It's best to use a ruler to measure the distance from the saddle to the handlebars, ensuring your arms are naturally bent and you don't feel too leaned forward or backward while riding. Different types of bikes have different requirements—for example, road bikes suit shorter stems for better handling, while mountain bikes tend toward longer stems for increased stability. Trying out samples of different lengths is very helpful. I often test cornering feel on slopes—it's safe and convenient. If your lower back doesn't hurt after adjustment, you've chosen correctly. Don't overlook these small details; they can greatly enhance the fun and endurance of daily commuting.
Choosing the right stem length is quite a technical task. I think a simple measurement can be done: after adjusting the saddle to normal height, lightly grip the handlebars with your hands, and keep your elbows slightly bent at about 15 degrees—this is the comfortable position. A stem that's too short makes steering responsive but unstable, while one that's too long results in clumsy handling and easy fatigue. Generally, for someone around 170cm tall, a 90-100mm stem is suitable, but personal preference also matters. In terms of riding dynamics, a shorter stem improves cornering efficiency during sprints, while a longer one reduces neck strain on long rides. Always check component compatibility to avoid buying the wrong one. I always recommend beginners start with a conservative length and adjust gradually, as comfort should come first—don’t rush to pursue extremes.
