When selecting a valve stem, the main considerations are length, height, stem diameter and material. But don't get too entangled, it is a relatively easy decision-making process when deciding what is right for you.

The handlebar stem seems to be a fairly standard device, but it has a huge impact on control and comfort. Getting the wrong size of the stem not only becomes a problem, but also the steering.

Thankfully, they are easy to replace and have a variety of options, so you can easily fine-tune your location.

Length

The stem length is a key factor to consider when buying. For too long, you will be stretched to the bar that may cause neck and shoulder pain. This can also cause control problems because you will be stretched farther when turning.

The steering is also affected by the length of the stem; too long, the steering will become slow and willful, while too short, the steering can be twitching and disturbing.

As a rule of thumb, you should not use stems shorter than 90 mm or longer than 130 mm on road bikes. If you need stem lengths beyond these limits, then your bike frame size is wrong. sorry!

Rise

The ascent (the angle from the fork to the rod) has a considerable effect. The rise is expressed in + or – degrees, because this determines the angle at which the stem will rise or fall from the front fork servo. The higher the degree (+), the straighter your position. Or, if you turn the rod upside down, the lower you will be.

Most riders will appreciate the rather low angle, ie. Less than 10°, because this gives a fairly neutral position, just a low rise. Casual riders will prefer a more upright posture. In order to obtain better aerodynamic performance, the racer will try to lower the body.

Don't forget, you can also raise and lower the stem by moving the spacer on the fork steerer tube. Usually you only need to replace a 10 mm gasket from below the valve stem to above the valve stem to achieve all the differences you need.

Note: Some manufacturers quote another way, namely 83°, which is actually a 7° rise, so don't expect a close-to-vertical stem!

Bar and fork clamp diameter

The top of the fork steerer tube is almost universally 1 1/8 inch—even though the front fork is over 1.5 inches in size at the fork crown—so most stem manufacturers don't even quote this clamping diagram.

Older bicycles have a 1-inch steerer, but these are becoming fewer and fewer, and any stem suitable for these types will be clearly marked.

Some bicycle manufacturers produce larger diameter front fork steering tube stems, but these products are very rare and clearly labeled.

Fortunately, nowadays, the diameter of the handlebar clamp is almost universally 31.8 mm (or 31.7 mm in some cases, but this is still suitable). Despite this, 31.8 is still called the "super size" (this is to distinguish it from the old 25.4 mm size).

The only exception to the size of this handlebar clamp is the new Deda 35 system. As you have guessed, it is 35 mm and requires a corresponding handlebar and stem.

Most rod clamps are 4-bolt styles, which are not only harder, but also help distribute the pressure of the clamp to a larger area on the rod, which is what carbon rod users will like.

Material

The main structural material of the stem is alloy. There are also some carbon models and some even more rare titanium models.

Alloy stems are relatively cheap and lightweight, so they are the most common models. Carbon fiber stems are lighter and very hard, but they are also more expensive, so they are usually favored by racers or heavyweight drivers.

Colour

Finally, the color of the stem cannot be ignored. Does it match your bike, handlebars, seatpost? It is a small consideration for some people, but once you have determined your position, there is no need to ruin it with the wrong aesthetics!

Having said that, there are usually not many colors to choose from. It is not as bad as "any color as long as it is black", but you will rarely see stems that are not white or black.

Which stem should you buy?

There are no hard and fast rules when choosing a stem. The main thing is to choose the one that suits you best. Two identical riders using the same bike may need different stems, so just make sure you have the one that best suits your needs.

Recreational riders will prefer a more upright, closer position because it is more comfortable and easier to control. Therefore, a rod length of no more than 100 mm and a 10 degree or ascending angle will be a good choice for most people.

Ordinary riders will want a fairly neutral position, so they will be slightly elevated according to their needs and position, such as 6° or 7°, and a medium length.

Racers will want the longest and lowest stem, they can escape and still control. This extended position is better for aerodynamics. Some people prefer light weight, while others sacrifice low weight for strength and stiffness, especially for larger riders and sprinters.

If you have your own ideas, please contact us(sales@top-fire.com) to discuss and provide you with customized services.