A suspension system

A suspension system is made up tires, air pressure in the tires, springs, and dampers.  This page explains the difference between springs and dampers (chassis suspension) and tires and air pressure (tire suspension).

 

Chassis suspension

When we think of mountain bike suspension, we normally think of suspension forks and rear shocks.  This kind of suspension is designed to isolate wheel movements from the frame and rider — the wheels move up and down with the bumps and the chassis stays smooth and level.  The chassis is suspended, the wheels are not.

One limitation of chassis suspension is the weight of the wheels, brakes, fork lowers — anything that is not supported by the suspension — has to accelerate and change directions extremely rapidly for the suspension to perform well.  

In suspension tuning, these components are known as "unsprung weight."  Unsprung weight is bad because it delays the suspension response time.  In short, the more unsprung weight, the worse the suspension.

 

Tire suspension

Tire suspension has virtually zero unsprung weight.  Only a tiny section of the tire deforms in response to a bump, and the mass of that portion of the tire is negligible. Because it weighs so little, it can accelerate and change directions extremely rapidly.

On the trail, this means that tires are much more efficient than a suspension fork at absorbing fast, sharp, high frequency bumps.  The obstacles where chassis suspension components struggle are the same obstacles where tire suspension shines.

 

cushcore tire suspension + chassis suspension

The ideal suspension system is CushCore Inner-Tire Suspension paired with effective chassis suspension.  With enhanced tire suspension, less compromise is required of the chassis suspension.  The fork and shock may be tuned for improved stability and optimal performance on the obstacles where they naturally work best — low frequency, high force impacts.  CushCore will deal with everything else.