An outdoor power equipment unit includes independent suspension system having a frame, a first wheel assembly, a second wheel assembly, a first laterally-extending suspension arm pair, and a second laterally-extending suspension arm pair. The first wheel assembly includes a first wheel and a first side suspension arm. The first side suspension arm is pivotably coupled at a first end to a first side structural member and is fixedly coupled at a second opposite end to a joint of the first wheel assembly. The second wheel assembly is arranged similarly to the first wheel assembly. Both the first laterally-extending suspension arm pair and the second laterally-extending suspension arm pair are configured to independently pivot about the frame to be vertically displaceable relative to the frame.