A vehicle suspension damper for providing a variable damping rate. The vehicle suspension damper comprises a first damping mechanism having a variable first threshold pressure, a second damping mechanism having a second threshold pressure, and a compressible chamber in communication with a damping fluid chamber, wherein the second damping mechanism is responsive to a compression of said compressible chamber.

A vehicle suspension damper for providing a variable damping rate. The vehicle suspension damper comprises a first damping mechanism having a variable first threshold pressure, a second damping mechanism having a second threshold pressure, and a compressible chamber in communication with a damping fluid chamber, wherein the second damping mechanism is responsive to a compression of said compressible chamber.

A spring assembly for mounting between a chassis and an unsprung mass of a vehicle, the spring assembly comprising a coil spring and a hydropneumatic spring acting in series, wherein the hydropneumatic spring is configured to be switchable between a compressible state and an incompressible state, such that when the hydropneumatic spring is in the compressible state, the equivalent spring rate of the spring assembly is a function of the spring rate of the coil spring and the hydropneumatic spring, and when the hydropneumatic spring is in the incompressible state, the equivalent spring rate of the spring assembly is a function of the spring rate of the coil spring.

Aspects of the present invention relate to a control system (100, 200) for a vehicle suspension system (300) of a vehicle (600). The control system comprises one or more controllers. The control system is configured to: determine that a first subsystem (302) of the plurality of connected subsystems is operating in a de-rated mode in response to a subsystem operating condition of the first subsystem being outside a predetermined operating window; and in dependence on determining that the first subsystem is operating in the de-rated mode, transmit a de-rate indicator to a further subsystem (304, 306) of the plurality of connected subsystems, wherein the de-rate indicator is configured to: indicate, to the further subsystem, that the first subsystem is operating in a de-rated mode; and cause the further subsystem to operate in a de-rate response mode, wherein the operation of the vehicle suspension system with the first subsystem operating in the de-rated mode and the further subsystem operating in the de-rate response mode provides a higher level of vehicle control in comparison to the vehicle suspension system operating with the first subsystem operating in the de-rated mode without the further subsystem operating in the de-rate response mode.

A suspension system configured to exhibit low variance in vehicle ride frequency over a large range of vehicle loads. The suspension system includes a strut having a cylinder and a piston configured to reciprocate in the cylinder. The suspension system also includes a vessel coupled to the strut, and a valve in an interior chamber of the vessel. The valve divides the interior chamber into a first liquid volume and a second liquid volume. The suspension system also includes a hydraulic accumulator having a volume and a liquid volume. The suspension system further includes a compressible liquid in the cylinder, the first liquid volume in the vessel, and the second liquid volume in the vessel, and a spring element in the volume of the hydraulic accumulator.

A system for vehicle load management including a processor and a memory in communication with the processor and including instructions that, when executed by the processor, cause the processor to receive a first indicator signal from a first sensor. The instructions further cause the processor to, based at least in part to the first indicator signal, determine a vehicle load intervention. The instructions further cause the processor to, based, on the vehicle load intervention, transmit one or more adjustment signals to cause one or more vehicle load adjustments to occur, the one or more vehicle load adjustments including at least one of at least one lire being inflated, the at least one tire being deflated, a liftable axle being raised, and the liftable axle being lowered.