How to determine your bike stem length? Things to keep in mind when choosing bike stems

How to determine your bike stem length? When choosing the right bike, one of the most important decisions is what stem length to choose.
A lot of people don’t know what stem length to choose when buying a new bike, which can lead to them choosing the wrong size or type of bike.
Josh Quigley has created this guide to help you choose the right bike stem length for your needs. Whether you’re a mountain biker or a road cyclist, we have the information you need to make an informed decision.

Bike stem – what is it?

The stem connects the handlebars to the steerer tube of the bicycle fork. It is an important component as it determines the fit and handling characteristics of a bike.
When choosing a stem, one important consideration is length. Generally, a longer stem will provide more reach and a more stretched out riding position, while a shorter stem will allow for quicker steering responses and a more compact riding position.
There is no one-size-fits-all approach to determining the appropriate stem length for a rider. Factors such as body proportions, flexibility, and preferred riding style all play a role in finding the best fit. It may also be necessary to experiment with different stem lengths in order to fine tune your position on the bike.
Stem length
Stem length is typically measured in millimeters, and is listed as the distance from the center of the handlebar clamp to the center of the steerer tube clamp.
It is important to note that stem length is just one aspect of stem fit. The angle of a stem, or its degree of rise or drop, also plays a role in determining rider position on the bike. It is possible to achieve a similar riding position with different combinations of stem length and angle.
When changing stem length (or angle), it is crucial to ensure that proper clearance is maintained between the handlebars and any other components such as brakes or shifters. It is also important to follow recommended torque specifications when tightening stem bolts to avoid damage to components.
Stem rise or drop
In addition to length, stem angle (also referred to as rise or drop) can also affect rider position and handling characteristics. A stem with a positive rise will bring the handlebars higher relative to the steerer tube, while a stem with a negative drop will lower the handlebars.
A stem with a lot of rise may be advantageous for more upright riding positions, or for riders who lack flexibility in the torso and arms. On the other hand, a stem with a significant drop can provide an aerodynamic advantage for riders looking to achieve a low and aggressive position on the bike.
Stem diameter
Another aspect of stem fit to consider is the diameter of the handlebar clamp. This should match the diameter of the handlebars in order for proper attachment. The most common standard for road bikes and mountain bikes is a 31.8mm handlebar clamp diameter, although some older or less mainstream models may have 25.4mm handlebar clamps.
It is also important to check compatibility with any accessories such as aerobar extensions or computer mounts, as these may require a specific clamp diameter in order to attach securely to the stem.
Stem material
Carbon vs alloy stems
Stems can also vary in the material they are constructed from. Most commonly, stems are made from either alloy (aluminum) or carbon fiber.
Carbon fiber stems tend to be lighter and more expensive than alloy stems. However, they may also have lower strength and stiffness, so it is important to carefully consider the intended use and weight limit of a carbon stem before purchasing.
Alloy stems offer reliable strength and durability at a lower cost, making them a popular choice for all types of riding disciplines.
Different types of bike stems
Road bike stems
Road bike stems are typically longer and more angular, with a lower rise to accommodate a more aggressive, aerodynamic riding position.
Mountain bike stems
Mountain bike stems tend to be shorter and have a higher rise to accommodate a more upright riding position on rough terrain. Some mountain bike stems also feature an adjustable angle for added versatility in handling different types of terrain.
Direct-mount mountain bike stems
Direct-mount stems feature a two-bolt clamp directly on the steerer tube, allowing for easier adjustment and a cleaner handlebar setup. These are most commonly seen on downhill mountain bikes.
Gravel bike stems
Gravel bike stems are often similar in shape and size to road bike stems, but may feature a slightly higher rise to accommodate a more upright riding position on mixed terrain.
Quill stems
Quill stems feature a hollow tube that inserts into the steerer tube and clamps with a bolt at the top, typically seen on older road bikes and some city/commuter bikes.
Bike stem standards
Stem length and angle are measured in millimeters, while stem rise is measured in degrees. Stems also have a designated clamp diameter to match the handlebar.
The most common handlebar clamp diameters are 31.8mm and 35mm, with some older bikes using 25.4mm. It is important to match the stem clamp diameter to that of the handlebars for proper fit and function.
Some stems also feature an additional shim to allow them to work with different handlebar clamp sizes – just be sure to check compatibility before making any adjustments. In addition, it is important to note that not all stem styles and brands may be compatible with your bike’s specific headset and steerer tube design, so double check before making any changes.
How to determine the length of your bike stem?

In order to determine the length of your current stem, you can measure the distance from the center of the handlebar clamp to the center of the steerer tube clamp. This can be done with a ruler or tape measure.
It is also possible to estimate stem length by comparing your riding position on your bike to that of another rider on a similarly sized bike with a known stem length.
When deciding whether or not to change stem length, it is always advisable to consult with a trained bicycle mechanic or fitting professional for guidance and assistance in making adjustments.
Remember, finding the right stem fit involves more than just length – keep all aspects of stem fit in mind as well as personal factors such as body proportions and flexibility in order to achieve the most comfortable and efficient riding position.
Apps for determining appropriate stem length

There are also several apps and online tools available that can help with determining appropriate stem length, such as BikeCAD and FitPro. However, it is important to note that these should be used as a guideline – consulting with a fitting professional or trained mechanic for recommendations on stem length and angle adjustment is always recommended. And don’t forget to follow manufacturer’s guidelines and have everything properly secured before heading out on a ride.
Guide to adjust a bike stem

There are a number of ways to adjust a bike stem, depending on the type of stem and desired adjustments.
To raise or lower the handlebars, you can change the stem angle by flipping it or using an adjustable angle stem. You can also achieve a similar adjustment by swapping out the stem for one with a different rise or drop measurement.
If you want to change the overall reach to the handlebars, you can do so by changing the stem length. This involves loosening and removing the stem bolts, swapping out the stem for one of a different length, and re-tightening the bolts to manufacturer’s specifications.
It is important to always consult with a trained bicycle mechanic or fitting professional before making any significant changes to your bike’s fit. They will be able to assist with proper adjustment techniques and ensure that all components are compatible and secure.
Figure out the right stem length your bike

Reasons to find out the right bike stem length
Bike stem length affects handling
Stem length affects handling and overall bike fit, so it is important to properly assess and adjust as needed for optimal performance and comfort while riding. Consulting with a fitting professional or experimenting with different stem lengths can help you find the perfect fit for you and your bike. Always remember to follow manufacturer’s guidelines and have a trained mechanic check that everything is secure before heading out on a ride.
Correct reach
Stem length alters the distance (reach) from the handlebar to the saddle, so finding the correct stem length is important for achieving a comfortable and efficient riding position.
Achieve your desired position
Finding the correct stem length can also help you achieve your desired position on the bike – whether you prefer to be more aggressive and aerodynamic on a road bike, or upright and stable on a mountain bike.
How to figure out the right stem length your bike
Experiment with stem length and angle
Don’t be afraid to experiment with stem length and angle to find the right fit for your riding style and comfort level. Just remember to always follow manufacturer’s guidelines and have a trained mechanic check that everything is secure before heading out on a ride.
Frame size-specific stem lengths
Bike manufacturers will often design a frame with a specific stem length in mind, so it is important to consider the size of your bike frame when determining appropriate stem length.
Do not copy the professional riders
It can be tempting to copy the stem length and angle used by professional riders, but remember that every rider is different – what may work for them may not necessarily work for you.
Next, we will walk you through things to keep in mind when choosing bike stems.
Things to keep in mind when choosing bike stems

Comfort
Without a doubt, the most important aspect to consider when finding the correct stem length is comfort. A comfortable riding position not only improves overall enjoyment, but can also increase efficiency and performance.
Aerodynamics
In road cycling, a more aggressive and aerodynamic position on the bike can often be achieved with a shorter stem length – but this may sacrifice comfort. Finding the right balance between aerodynamics and comfort is key.
Handling
Stem length can also affect handling – a shorter stem typically results in quicker handling, while a longer stem will generally provide more stability at high speeds. Experimenting with different stem lengths can help you find the perfect balance of quickness and stability for your riding style.
Stability
In mountain biking, particularly in technical and rough terrain, a longer stem can provide more stability on the front end of the bike. Again, finding the right balance between stability and comfort is key.
Responsiveness
In BMX and freestyle riding, a shorter stem length can provide a more responsive and agile feel when performing tricks and maneuvers.
Steerer tube diameter
It is important to also consider the diameter of your steerer tube when selecting a stem – as stems are available in 1 inch and 1 1/8 inch sizes, and some brands may have their own sizing.
Handlebar diameter
Lastly, the diameter of your handlebars should also be considered when selecting a stem – as stems are available in both 25.4 mm and 31.8 mm sizes.
Stem price
The price of a stem can vary greatly – from basic and affordable options, to high end and lightweight stems made with specialized materials. However, it is important to keep in mind that a higher price does not necessarily mean a better fit for your bike or riding style.
F.A.Q bike stem length
How do I choose the right stem length?
Consulting with a fitting professional or trained mechanic for recommendations on stem length and angle adjustment, experimenting with different lengths to find the perfect fit for your riding style and comfort level, and considering frame size and manufacturer’s design guidelines are all important factors in choosing the right stem length.
How do I know what size stem I need for my bike?
Your bike’s manufacturer should have specific design guidelines for the correct stem length, and consulting with a fitting professional or trained mechanic can also provide recommendations.
Is 70mm stem too short for road bike?
This ultimately depends on individual riding style and comfort level – some riders may find a 70mm stem to be the perfect fit, while others may prefer a longer or shorter length. Experimenting with different stem lengths can help you determine the best fit for you.
Is a 90mm stem too short?
Again, this ultimately depends on individual riding style and comfort level – some riders may find a 90mm stem to be the perfect fit, while others may prefer a longer or shorter length.
Conclusion
When it comes to bike stem length, there is no one-size-fits-all answer. What’s important is that you find the right length for your body and riding style. Our team at Big Buddy Bike can help you find the perfect stem length for your needs – just visit our website to learn more. Thanks for reading!