How To Measure A Bike Stem

The headset rests on the top of the steering head that holds the steering column.

How to measure a bike stem. Stem length designated in millimeters may be indicated on the stem. Generally speaking stem lengths on road bikes vary from 80 to 140mm with 100 to 110mm perhaps the most common sizes. Lenghts and angles differ and are important when fitting a bicycle to suit a rider. This size specific approach goes a long way to getting you set up with the correct stem length providing you ve chosen the right size frame another area where a bike fit comes in useful.

In order to alter stem length you must first know the length of your current stem. Still standing measure to the top of the book from the floor. However most stems are not marked and must be measured in order to determine size. Measured from an imaginary line perpendicular to the steering axis to the center of the stem extension.

Stem length is one aspect of a road bike that you can alter to increase both comfort and performance. Look for the headset on your mountain bike. How to measure a bike stem. A zero rise stem for example is essentially straight while a stem with a rise of 10 has a 10 angle between the steerer and handlebar clamp areas.

The stem rise refers to the stem s angle in degrees relative to the fork steerer tube and affects bike positioning and reach. If you are sizing a mountain bike measure in inches. For the most precise measurement. Picture 2a shows a quill stem with a shorter neck angled downwards next to a threadless stem with a longer neck.

Take a thick hardcover book and sit on the spine as if it was your bike seat. Important dimensions and how to measure. Measured from the center of the actual steering axis to the center of the stem extension. On stems with built in rise this measurement will be made along an imaginary line as seen in the diagram.

The useful length of the stem measured from the center point of the steering bore to the center of the handlebar clamp except accounting to rise on stems this measurement may be made along an imaginary line. Stems are made with various lengths and angles.