How is bike stem length measured

Road bikes are likely to have a mostly horizontal stem with little or no rise since they tend to have more aggressive rider positions than other styles of bike. To measure your stem, you first need to mark the center point where the stem attaches to the bike frame and the center point where it attaches to your handlebars. The length between the two parts is always shorter than your true stem length. Lean your bike up against a wall or stabilize it with a bike rack or frame.

Now, take a tape measure with centimeter and millimeter markings in addition to inch marking. Measure from the two center points you identified earlier, in either millimeters or centimeters. That is:. You can either use a paper to draw the distance, or you can use a ruler and measure from the handlebars to the frame connection without following the angle of the stem.

Length is a combination of reach and rise, so knowing your reach will help you make the exact adjustment you need, without changing your stem in other dimensions. There are connectors to help adapt stems and frames of different width, though. While you need to know your stem width, there are usually plenty of adaptor options. To measure the width, just measure with the tape measure perpendicular to the stem.

A stem measured length is usually assigned in millimeters, and you can sometimes see this indicated on bikes. However, there are still stems that do not put out their length measurements, so you have to determine them yourself. The first thing to do is to place your road bike against something firm.

Putting it against firm support will give you access to a good stem angle and position that may be useful for the bike stem measuring process. You can stabilize your bicycle frame by putting it in a trainer or a bike frame stand. However, if these tools are not available, you can always position your bike frame against the wall or something firm. Length is very influential to the stem. Before you measure bike stem length, know that its stated length is not the same as the length of the whole stem from its front to back.

Ensure that you measured the length in centimeters or millimeters. A bike stem length usually runs in 10 mm increments and starts from 70 mm to mm. Do know that the measurements you get are possibly off by a few millimeters.

These two steps are the only thing you need to do to accurately measure stem length and never experience spending money on inaccurate measurements of a bike stem. Note: A threadless stem is somewhat unique compared to a threaded stem, and the difference lies in their steerer tube.

Regardless, a threadless stem and a quill stem both have rise and drop, which are measured in degrees. Reach must also be prioritized.

A bicycle with insufficient reach is usually uncomfortable as it causes cramping. It will tell you how far you could go before you meet any negative handling traits.

I do not recommend putting a little stem on bikes with a shorter top tube as it would not end in smooth control and a good riding position. The two most common stem types are threadless and quill stems. The stem required for your bike must be compatible with your headset and fork. A threadless stem clamps around the steering column and is held in place by tightening the pinch bolts.

If you are replacing your bike stem look for a modern 4-bolt design. They are stronger, stiffer and creak less than their predecessor 2-bolt face plates. But beware of shifting trends.

A quill stem attaches to the inside of the steering column through compression by inserting the stem and tightening a bolt on the top that pulls the stem up. They are sized down for the internal diameter of the tube. Industry standard for quill stems has been one inch for decades.

The measurements are taken perpendicularly from the center line of the steerer tube to the center of the handlebar clamp. Threadless and quill bike stems still need to be compatible with your handlebar diameter. They both slide on and are fastened in place by bolts. There are two sizes of handlebar diameters: For example, if a manufacturer advertises a 7 degree angle using Angle A, we may describe this as 97 degree. Rise mm : The effective height gained as a function of the stem's angle and length.

Measured vertically from the center of the handlebar clamp to an imaginary line that bisects the central meeting point of the extension and vertical portion of the stem.