In today's bike market, you can find stem in almost every length and angle to be as flexible as you need to be. While the stem will trump all other factors for comfort and proper stem position, what about the handling and steering performance associated with stem length?
Almost since the invention of the bicycle, the length of the stem has been a key component of adjustment. Although the options were very limited in the early designs, adjustable length stem quickly became available.
Nowadays, materials and technology have advanced so much that fixed length stems have long since replaced adjustable stems. We can choose from lengths ranging from 50mm to 150mm as well as a wide range of angles that can be adjusted to any position you need. This great adjustability allows riders to consider using a variety of different frame geometries, especially for those who choose to customize their bikes. But the question arises: is it better to have longer or shorter stem on your bike? Or is there an optimal length?
There is no simple formula to follow
The field of bicycle manufacturing is undoubtedly the most vocal when it comes to the optimal length of stems. After all, they are in the business of providing their customers with the ideal bike, and part of that process involves the question of the optimal stem length for each frame they build.
The length of the stem will change with the design of the bike. It must also meet the rider's comfort, biomechanical, and performance needs as well as the bike's steering and handling. Determining the optimal stem length depends on the level of priority the rider chooses for themselves, as the relaxed position tends to affect performance and the most optimal biomechanics are not always possible.
Obviously, there is no simple formula for determining the length of a stem, and the solution is highly individualized. However, there are two metrics that are well worth discussing as it affects every rider.
Weight distribution
Let's start with the assumption that we have a frame that is adjustable for REACH and has the same total front deformation after each change to a different length of stem. With this in mind, the length of the stem determines the weight distribution on the front wheel.
Ideally, the rider's weight should be as close as possible to the point of contact between the front wheel and the ground. A long reach frame with a short stem will make you feel very floaty on the front wheel. However, if the weight is distributed behind the contact point of the front wheel it will again make your steering maneuvers vague and distribute less weight on the front wheel.
Radius of steering
When comparing a short stem to a long one, the longer stem has a greater leverage ratio for the same steering angle and requires a longer arc of movement to steer the same angle. The shorter stem provides a more direct response, but the shorter stem is more susceptible to physical influences, which can lead to a "false-fuzzy effect".
As a result, a short stem can make a fast-steering bike unstable, whereas a long stem is more stable. For example, if the bike already has a small angled head tube, a long stem will make steering much slower.
About stem lengths for women's bikes
Due to the differences in body structure between men and women, women tend to need a shorter stem to accommodate their shorter torsos.
Summary and conclusions
In most cases, riders don't have much freedom of choice, but can only fine-tune them to adjust their position on the bike. What we can do is to take the length of the stem into account when choosing a frame, so that we can choose a frame with a style that suits us better.
When looking at the geometry of the bike, the stem length has relatively little effect. Most riders can quickly adapt to different lengths of stem as long as they fit within their desired range. That said, finding the right stem length for you will improve the steering and handling quality even further, getting closer to perfection. But it is not a critical key to changing handling and steering.
Post time: 2024-01-08 17:14:30
