The proportion of sprung to unsprung weight a vehicle has directly
effects cornering performance and traction. What is sprung and unsprung
weight and how does it effect cornering on a bicycle?
Unsprung weight is the portion of the bicycle and rider that is not
suspended (fig A1). The more unsprung weight that is forced to respond
to the road, the slower that weight is able to react, resulting in less
consistent tire contact with the road. On a rigid bicycle, the vast
majority of the weight is unsprung. Sprung weight on the other hand, is
the portion of the bicycle and rider that is suspended and does not
need to adapt to the road beneath it in order to maintain traction (fig
A2).
Suspension changes most of what is unsprung weight on a rigid bike into
sprung weight, drastically reducing the weight that has to adapt to the
road. Suspension takes the load off the wheels and tires, allowing them
to react faster and more accurately to the road below them. This
reduces tire deflection, keeping tires in more consistent contact with
the surface below them and is why suspension enhances traction and
allows the rider to corner faster and with greater confidence (fig B1).
