Road Bike Stem Length Measurement

The most significant thing while choosing a road stem is the length of the stem may be the key factor for overall fit of the bike.

Road bike stem length measurement.

Important dimensions and how to measure. It must also address the rider s comfort biomechanics performance needs and the steering and handling of the bike. We often refer to this as the stem length. Lenghts and angles differ and are important when fitting a bicycle to suit a rider.

Shorter stems result in noticeably quicker and more responsive handling that is a definite advantage on technical singletrack and gravity riding. Generally speaking stem lengths on road bikes vary from 80 to 140mm with 100 to 110mm perhaps the most common sizes. On stems with built in rise this measurement will be made along an imaginary line as seen in the diagram. Stems are made with various lengths and angles.

Whereas road riders tend to choose stem length based solely on overall bike fit and positioning for off road riders the length of the stem is critical in determining how the bike handles. Riders like to get a long small and aerodynamic position of the bike e g spirited racers can choose for a longer 1200 mm stem for optimum stretch. Sometimes you might need to customise the stem length yourself though. Stem length is one aspect of a road bike that you can alter to increase both comfort and performance.

The wrong stem length will not only make it difficult to reach for the handlebars it will also destabilize the steering and affect body position on the bike. The best average stem length for modern mountain bikes falls between 50 mm and 80 mm. The effective length of the stem measured from the centerpoint of the steering bore to the center of the handlebar clamp without accounting for rise. Stem length designated in millimeters may be indicated on the stem.

Some manufacturers specify different length stems in relation to the frame size to try and offer the best fit. Stem length will vary with the design of the bike. 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. Picture 2a shows a quill stem with a shorter neck angled downwards next to a threadless stem with a longer neck.

However most stems are not marked and must be measured in order to determine size. Road bike stem length guide bike stems look like a standard equipment without any science to it however they are highly influential when it comes to comfort and control.