Single Pivot Suspension Design

January 30, 2009 by  
Filed under Frames

A single pivot design is the simplest possible design for rear suspension system. Essentially this design consists of the rear axle being mounted into a swingarm which actuates a spring damper suspension unit (shock) via leverage on a single pivot. An example can be seen in the image below. This is the most basic and most commonly used suspension linkage available on the market and was directly modelled on the motorcycle industry’s standard design.

single pivot suspension design Single Pivot Suspension Design

Although the concept is essentially very simplistic, consideration must be given when deciding the location of the pivot and the shock mounting points. For example an apparently insignificant change in pivot position will alter the axle path, and therefore dramatically change how efficiently the bike pedals and reacts to bumps.

Mountain bikes will experience lateral forces on the wheels when cornering, landing slightly sideways, or going through very rough terrain. It is difficult to make single pivot bikes as laterally stiff as multi pivot bikes due to the moments all being transferred through just one pivot. As a result of these thrust loadings on the bearings they tend to wear out faster. However this is not a big problem due to the fact that the bearings used are normally standard sizes, hence affordable, and easily purchased when requiring replacement.

Related Posts