How to choose your bike stem
The stem is the part that connects the handlebar to the fork's steerer tube of your bike. A bike stem is characterized by its length and inclination. It influences the cyclist's position on the bike. So how to properly choose your road bike stem or your MTB stem? This is what this guide's for!
Which stem for which practice?
- For a sport practice where one tends to seek performance, a rather long stem (more than 100 mm long) wich isn't very inclined should be preferred. It will make the cyclist lean effectively on their bike, thus gaining in aerodynamics and pedaling power to the detriment of comfort.
- Some practitioners even tend to apply a negative inclination by the use of a reversible stem (recognizable by the mention '+/-' indicated before the degree of inclination).
- Practitioners who favour comfort are better off with a medium stem between 60 and 100 mm with an inclination varying between 10 and 15° so they can find a more upright and comfortable position.
- Lastly, for extreme mountain biking practices (Enduro, Freeride, DH, Dirt), go for very short stems from 0 to 60 mm with a strong inclination (up to 20°) to obtain a very rearward position on the bike and to gain in manoeuvrability.
As you will have guessed, the choice of a new stem can greatly influence your position and your sensations on the bike. Before you start, you have to know your bike well (distance between the saddle and the head tube, inclination of the steerer headtube) and to know yourself ('am I flexible enough to take an extreme position on my bike ?'). Finally, make your objectives clear (remove pain, increase performance...).
What measures to take?
To be sure to choose a stem compatible with your headset, first measure the top diameter of your fork's steerer tube, then the diameter in the middle of your handlebar.
The inclination value announced by the manufacturers is givenin relation to a horizontal plane (see the plan below). The steerer's tube inclination must also be taken into account to choose a new stem, as this parameter can considerably vary depending on the models and the brands!
The stem lenght indicated by the manufacturers is measured from axis to axis as shown in the following diagram: