Stem lengths, what gives?
When it comes to road cycling, achieving the ideal fit on your bike is crucial for both comfort and performance. One of the key components that play a significant role in bike fit is the stem. The stem is the part that connects the handlebars to the head tube, allowing you to control the front end of the bike. Though often overlooked by casual cyclists, the length of your stem can greatly influence your riding experience. Through my time bike fitting, I’ve realized how different stem lengths can make a huge difference in how your bike handles, how comfortable you feel, and how efficiently you perform.
Below, I’ve highlighted some important considerations for stem lengths and how they affect your cycling experience. We will only apply these principles to road bikes, but you can imagine how this may differ on gravel or TT or MTB.
Typically, I enjoy working with Zipp stems. Their Service Course 6061 aluminum stems are fantastic and the lifetime warranty isn’t too shabby either.
1. Stem length and bike fit: finding the sweet spot
The length of the stem directly impacts your bike's fit, which is crucial for both comfort and performance.
Shorter Stems (60-90mm): Shorter stems are often favoured by riders who want a more upright riding position. Despite being less aero, it may be a position of comfort, especially if someone has an injury history like neck or back pain or even surgery. These stems bring the handlebars closer to the rider, reducing the reach to the handlebars and offering a more relaxed, less aggressive posture. Shorter stems are beneficial for people with a shorter torso or for those who want more maneuverability, such as during technical riding or cornering.
Longer Stems (110-140mm): Longer stems, on the other hand, increase the reach to the handlebars, resulting in a more stretched-out and aero riding position. This is preferred by riders who need more stability, control, or aerodynamic advantages during high-speed rides or races. A longer stem can also benefit cyclists with a longer torso or those looking to adopt a more aggressive riding posture for optimal power transfer.
The right stem length depends on your body proportions and the type of riding you do. For competitive cyclists looking for speed and performance, a longer stem may be beneficial to reduce wind resistance and improve stability at high speeds. For casual riders or those focused on comfort, a shorter stem may provide a more relaxed, upright position that eases strain on the back and shoulders. For some, it may not be about any of those variables and that’s where the discussions we have during a bike fit really matter.
2. Handling and steering response
Stem length plays a crucial role in how the bike handles, particularly when it comes to steering response and stability. A longer stem provides more stability at high speeds and on fast descents, while a shorter stem can make the bike more agile and responsive in tight corners or technical situations.
Shorter Stem (Enhanced Agility): Shorter stems result in a quicker, more responsive steering input. This makes them ideal for riders who enjoy technical riding or racing in tight, twisty environments. The quick response makes it easier to navigate corners and respond to sudden changes in direction. However, a very short stem may make the bike feel twitchy or unstable at high speeds, especially for riders with less experience.
Longer Stem (Increased Stability): Longer stems offer more stability, particularly at higher speeds or when riding in a straight line. The longer reach gives you more control when descending or riding at high speeds on the road, as it makes the bike less twitchy and more stable. This stability can be critical for riders who prefer a more controlled, secure feeling when cycling on fast descents. However, a longer stem might feel less responsive in tight turns or when dealing with pedestrians in the bike lanes on the Lakeshore.
In general, choosing the right stem length is a balance between achieving the desired stability for speed and the responsiveness needed for more agile maneuvering.
3. Comfort and posture: preventing fatigue and discomfort
The length of the stem directly influences your body’s posture while riding, and this can have a huge impact on long-term comfort. Incorrectly sized stems can result in an uncomfortable riding position that leads to fatigue, neck pain, lower back pain, and even numbness in your hands or feet. Ensuring that your stem length is tailored to your body type and riding style can help prevent these issues, whether this is done during the construction of your bike or bike fit.
Shorter Stems (Less Reach): Shorter stems allow you to maintain a more upright riding posture. This can reduce strain on your lower back, shoulders, and wrists, which is particularly beneficial for longer rides or for cyclists with less flexibility. The more relaxed posture provided by a shorter stem may also reduce the risk of fatigue and discomfort over time.
Longer Stems (More Reach): Longer stems often result in a more stretched-out position, which can lead to better aerodynamics but may also cause discomfort, particularly for riders who are not used to a more aggressive, forward-leaning posture. On the flip side, if your stem is too long for your body, you may experience neck pain, shoulder tension, or lower back discomfort after long rides. However, experienced riders or those with a more flexible posture may find the longer reach comfortable and beneficial for generating power and speed.
For optimal comfort, it’s important to find a stem length that matches your body proportions. During your bike fit, there are a couple of measurements we strive for when factoring in the stem length from the perspective of saddle comfort as well as cockpit proportions, but these are not hard and fast rules, it depends.
4. Performance: power transfer and aerodynamics
For competitive cyclists or anyone looking to maximize performance, stem length is an important factor in optimizing power transfer and aerodynamics. The position of the handlebars in relation to the saddle can impact the way you transfer energy through the pedals.
Shorter Stem (Improved Comfort, but Less Aerodynamic): While a shorter stem may make you less aero this may decrease the overall aerodynamic efficiency at high speeds, it can still offer significant power transfer benefits, especially for cyclists who need a more relaxed position for endurance rides.
Longer Stem (Better Aerodynamics): This posture can help competitive cyclists reduce wind resistance, making it easier to sustain higher speeds for longer periods of time. A more aggressive, forward-leaning position is also generally better for transferring power from your legs into the pedals.
Some of my last thoughts
One of the major benefits of varying stem lengths is the ability to fine-tune your bike fit to your specific needs and preferences. Since each rider’s body proportions, flexibility, and riding style are unique, being able to adjust the stem length allows for a more personalized fit.
Cyclists who experience discomfort with their current stem length can experiment with different sizes to achieve a more optimal setup. During a bike fit, stem lengths can be swapped out relatively easily, making it an accessible way to improve fit without the need for expensive modifications.
With a lot of companies playing with mono bars like the Black Inc Barstem, yes it’s badass, and looks super aero but once you’ve picked your stem length (in mm) of 90/100/110/120/130, you’ve committed to the bit, and there’s very little we can play with from a bike fit perspective with the stem specifically. In that moment, we’d probably look to adjust many of the other variables available to us.
Ultimately, the right stem length depends on your body type, riding style, and specific needs. By experimenting with different stem lengths and adjusting for the best fit, you can significantly improve your comfort, control, and performance on the road.