Abstract: A vehicle snowplow system with an adjustable-bias tripping mechanism. The system includes a snowplow blade or moldboard which is pivotally mounted to a frame, the latter being adapted for mounting to a vehicle. The moldboard "trips" or pivotally moves between a normal plowing position and a displaced position when a lower region of the moldboard contacts a rigid obstruction. The system includes at least one biasing assembly operable to bias the moldboard toward the normal position with a biasing force, the biasing assembly configured so as to provide an adjustment to the biasing force to compensate for variances in roadway or environmental conditions.