Pressure-sensitive vales are incorporated within a dampening system to permit user-adjustable tuning of a shock absorber. In one embodiment, a pressure-sensitive valve includes an isolated gas chamber having a pressure therein that is settable by a user.

A damper includes a pressure-sensitive damping control circuit that selectively permits fluid flow from a first chamber to a second chamber. A piston varies a volume of the first chamber. A blow-off piston is movable between a closed position, wherein fluid flow through the control circuit is substantially prevented, and an open position, wherein fluid flow through the control circuit is permitted. The damper also includes a first source of pressure. A fluid pressure created by compression of the damper applies an opening force to the blow-off piston moving the blow-off piston in a direction toward the open position against a resistance force provided by the first source of pressure. The resistance force exceeds the opening force until the pressure created by forces tending to insert the piston rod into the first fluid chamber exceeds the pressure in the first source of pressure by a predetermined amount.

A damper includes a pressure-sensitive damping control circuit that selectively permits fluid flow from a first chamber to a second chamber. A piston varies a volume of the first chamber. A blow-off piston is movable between a closed position, wherein fluid flow through the control circuit is substantially prevented, and an open position, wherein fluid flow through the control circuit is permitted. The damper also includes a first source of pressure. A fluid pressure created by compression of the damper applies an opening force to the blow-off piston moving the blow-off piston in a direction toward the open position against a resistance force provided by the first source of pressure. The resistance force exceeds the opening force until the pressure created by forces tending to insert the piston rod into the first fluid chamber exceeds the pressure in the first source of pressure by a predetermined amount.

Altering the damping rate of a vehicle suspension damper. A pressure of a damping fluid is exerted against a second valve mechanism connected to the vehicle suspension damper. The pressure of the damping fluid is increased beyond a threshold of the second valve mechanism that is adjustable by an adjustment member. The adjustment member is exposed through a high pressure side of the vehicle suspension damper. The second valve mechanism is then opened.

A compression damper of a shock absorber includes: a single adjustable fluid circuit configured for controlling a damping rate associated with multiple compression speeds of the shock absorber, wherein the single adjustable fluid circuit includes a fluid passageway through a base valve; and a positionally adjustable floating shim stack positioned at one end of the fluid passageway, the positionally adjustable floating shim stack configured for selectively blocking a flow of fluid through the fluid passageway.

A compression damper of a shock absorber includes: a single adjustable fluid circuit configured for controlling a damping rate associated with multiple compression speeds of the shock absorber, wherein the single adjustable fluid circuit includes a fluid passageway through a base valve; and a positionally adjustable floating shim stack positioned at one end of the fluid passageway, the positionally adjustable floating shim stack configured for selectively blocking a flow of fluid through the fluid passageway.

A vehicle suspension damper including: a cylinder; a piston assembly; and an adjuster, wherein the piston assembly compresses fluid as it moves within the cylinder and the adjuster obstructs fluid flow from a first side of a damping piston of the piston assembly to a second side of the damping piston.

In a vehicle suspension, a preload is adjusted by selective engagement of cam surfaces of different heights with a cam receiving part by rotation of an adjuster part, the adjuster part includes a vertical wall part erected in an axial direction of a spring from a spring receiving part and an engaging part with which a tool to rotate the adjuster part is to be engaged, and the engaging part includes a first engaging part formed by a gap between the plurality of vertical wall parts disposed separately from each other in a circumferential direction of the adjuster part and a second engaging part formed by a hole penetrating the vertical wall part.

A shock absorber may include an elongated housing that contains damping medium, a piston rod with a first piston that divides the elongated housing into a rebound volume and a first compression volume, a second piston configured to move through a second compression volume, a third piston configured to move through a third compression volume, and a mount cap for the elongated housing. The mount cap may include a bleed circuit that leads from the third compression volume to the first compression volume. The second and third pistons may be configured so as only to be engaged when necessary to prevent the shock absorber from bottoming out in a compression stroke. A user-accessible adjuster mechanism on an outside of the shock absorber can be manipulated to close, open, or partially open the bleed circuit and thereby adjust the damping characteristics of the second and third pistons.

A shock absorber may include an elongated housing that contains damping medium, a piston rod with a first piston that divides the elongated housing into a rebound volume and a first compression volume, a second piston configured to move through a second compression volume, a third piston configured to move through a third compression volume, and a mount cap for the elongated housing. The mount cap may include a bleed circuit that leads from the third compression volume to the first compression volume. The second and third pistons may be configured so as only to be engaged when necessary to prevent the shock absorber from bottoming out in a compression stroke. A user-accessible adjuster mechanism on an outside of the shock absorber can be manipulated to close, open, or partially open the bleed circuit and thereby adjust the damping characteristics of the second and third pistons.