Many older bikes and some lower-end bikes have threaded steerer tubes. Threadless stems will typically have 1—3 pinch bolts D used in conjunction with a compression slot E to hold the stem to the steerer tube. They will also have 2—6 bolts F securing the faceplate G , although in some cases they hook on with one side and bolt on with the other. Stems come in different steerer tube and handlebar sizes.
It is wise to measure your components to ensure that you are installing or ordering the correct stem. Some common handlebar diameters are There are some outliers on some older bikes.
To determine the diameters of the steerer tube and bar, measure right where the stem will clamp using a metric caliper. Be sure to be accurate as some clamp diameters are within fractions of a millimeter of each other and are not cross-compatible.
It is difficult to determine the clamp diameter of the stem by measuring it. The clamp diameter is typically engraved or labeled on the stem, but sometimes it is not.
Incompatible components can be a safety hazard, so always double-check with the manufacturer for specifications and compatibility information. Stems also come in different lengths — measured from the center of the steerer tube to the bar center — and angles — typically between 0 and 20 degrees. These measurements are generally marked somewhere on the stem or its packaging.
Stems can be installed in an up or down position to adjust the bar height without changing spacer orientation. This is often referred to as positive and negative rise. When making drastic changes to the angle or length of the stem, changes to housing length may be required. Stems are usually accompanied on the steerer tube by spacers. These spacers come in a multitude of different thicknesses, colors, and materials.
They allow for height adjustment, and they also play a role in headset adjustment. When installing a new stem it is important to pay attention to the height of the stem and the amount of spacers that you were running before. Note that a new stem may have a shorter or taller stack, which you will then need to account for with more, fewer, or different spacers.
This procedure can be done with the bike in a repair stand with the front wheel removed, or on the ground. It can be helpful to straddle the bike for stability. Once you have the faceplate off, the bars will be hanging free. It is good practice to use a toe strap or something similar to suspend the bars and keep the cable and housing from kinking.
Next we will remove the top cap, but before we do: note that it is currently the only thing keeping the fork from falling out of the bike. Note: Make sure the top edge of your headset spacers or stem are slightly higher than the length of your steer tube.
This is required to properly tighten the headset. Place the headset cap on your steer tube and tighten the headset cap bolt into the star nut using a hex tool see Figure 9. Before setting the final torque on your headset cap bolt, make sure your stem is aligned straight with respect to the frame. Once everything is properly aligned torque your headset cap bolt to the manufacturers recommended torque value.
Tighten the steer tube clamp bolt s on your stem to secure it to the steer tube. Be sure to follow your stem manufacturers recommended torque value. Remove the faceplate of your stem in preparation for installing the handlebar see Figure Place your handlebar into the handlebar clamp and put the stem faceplate back into place see Figure Carbon fiber stems and handlebars often have torque ratings to low to prevent the handlebar from being held securely in place.
Carbon fiber glue helps create a better bond and prevents handlebars from shifting out of place. Tighten your stem faceplate bolts using a hex key finger tight only see Figure Torque the faceplate bolts to the manufacturers recommended torque value using a torque wrench. You now have a properly installed fork, headset, stem and handlebar see Figure This completes the installation of your fork, stem and handlebar. We hope you enjoyed this how to article.
For more great content, please register for our free monthly newsletter at the top of the column on the right. This allows shifting gears without having to remove a hand from the bars, unlike previous down tube shifting systems.
These can be used on almost any type of bike and are typically used for custom builds. Try touching your elbow to the nose of the saddle and reaching forward towards the handlebar with your hand. Reach: Horizontal distance from the center of the handlebar top to the center of the furthest extension of the bend, where brake hoods are mounted.
A reach of less than 80mm is short; mm is medium; 85mm or more is considered long. Generally speaking, a lower handlebar height reduces your centre of gravity. By placing more weight over the front wheel, you increase traction.
Additionally, a lower bar height provides a more centred position between both wheels to improve bike control, especially during climbing. Take the upright positioning of an endurance road bike, which alleviates strain on back, neck, arms, and hamstrings, and drops the rider a few millimeters down. Doing this positions the rider closer to the ground, lowers their center of gravity, and makes them more stable on uneven terrain. If you do find that your feet are flat on the ground, then your saddle is too low, and it will need to be raised.
Think simple aerodynamics.
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