Road Bike Stem Length Measurement

Picture 2a shows a quill stem with a shorter neck angled downwards next to a threadless stem with a longer neck.

Road bike stem length measurement.

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. Sometimes you might need to customise the stem length yourself though. On stems with built in rise this measurement will be made along an imaginary line as seen in the diagram. Good bike shops will be very helpful in helping you get the right stem length on your new bike or buying a new stem doesn t have to cost a lot of money.

Stem length will vary with the design of the bike. Shorter stems allow for quicker handling and are preferred by many downhill riders whereas cross country riders enjoy longer stems for their superior climbing performance. It must also address the rider s comfort biomechanics performance needs and the steering and handling of the bike. 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.

Important dimensions and how to measure. 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. In order to alter stem length you must first know the length of your current stem. Stem length designated in millimeters may be indicated on the stem.

However most stems are not marked and must be measured in order to determine size. Stems are made with various lengths and angles. 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. Some manufacturers specify different length stems in relation to the frame size to try and offer the best fit.

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. Generally speaking stem lengths on road bikes vary from 80 to 140mm with 100 to 110mm perhaps the most common sizes. We often refer to this as the stem length. Shorter stems result in noticeably quicker and more responsive handling that is a definite advantage on technical singletrack and gravity riding.

Stem length is one aspect of a road bike that you can alter to increase both comfort and performance. 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.