LAS VEGAS, Nev. — LiquidSpring LLC displayed its revolutionary CLASS suspension system at the 2012 International LCT Show in Las Vegas last month. CLASS is an acronym for Compressible Liquid Adaptive Suspension System. It is designed to replace conventional vehicle springs and shock absorbers with a compressible fluid as the spring and damping medium in combination with an electronic control system for automatic leveling and change of spring rate.
The CLASS system is available for the Ford F-550 and E-450 chassis. The system responds to various road conditions and driving styles by automatically and instantaneously adjusting spring stiffness and damping at each wheel independently to increase roll control and stability. The technology of the CLASS system replaces steel or air springs. It eliminates the need for shock absorbers and does not have the vagaries of air springs, such as condensation.
The system offers two modes: Comfort and Sport. The Comfort ride mode results in the system minimally using higher strut spring stiffness to maximize ride comfort while maintaining handling control. The Sport mode results in the system moderately using higher strut spring stiffness to improve handling control while maintaining ride comfort. The spring stiffness is changed instantaneously and automatically based on how the vehicle is driven. Normally, the strut is in its softest spring stiffness (see Fig.1) with all the compressible fluid active, but is changed on demand to a higher spring stiffness by closing a rate valve (see Fig.2) thereby reducing the amount of active compressible fluid. LiquidSpring offered a test ride on a CLASS-equipped bus to LCT assistant editor Michael Campos during the 2012 International LCT Show. The ride included a slalom segment, an aggressive lane-changing segment, an off-road segment, various cornering portions as well as driving over rough roads and railroad tracks.
The most notable impression was that the compressed-liquid spring suspension system eliminated the bounce and rattle normally felt when driving over bumpy or rocky roads. In fact, the difference between driving on the street and going off-road was barely noticeable. The bus felt stable throughout the corners, the slalom, and the lane-changing tests.
While Sport mode offered a firmer feel during the more aggressive driving sections, Comfort mode was still relatively steady and the riders didn’t experience any head-whipping. The test ride on the CLASS system was quite impressive but was one of those things that must be experienced in person to adequately understand because words don’t do it justice.
The system also features a user-friendly driver interface for changing system ride modes and ride heights (fig. 3). The software is tunable for different chassis and body combinations with different ride modes.
For more information about the CLASS system, please contact Carl Harr at LiquidSpring (765) 474-7816.
— Michael Campos, LCT assistant editor