A windshield wiper system in which a flexible cantilever arm to which a wiper blade is attached is preloaded against a rigid support. An additional preload is induced in the cantilever arm as the wiper system is installed on a vehicle with the wiper blade in the horizontal inwipe position and bearing against the windshield. This creates an initial separation between the cantilever arm and the rigid support. As the rigid support and the cantilever arm move together from the horizontal inwipe position to the vertical outwipe position, the separation between the rigid support and the cantilever arm decreases, so that, with the increased contact between the rigid support and the cantilever arm, there is a change in the cantilever arm support location and a shortening of the cantilever arm beam. Conversely, as the rigid support and the cantilever arm move together from the vertical outwipe position to the horizontal inwipe position, the separation between the rigid support and the cantilever arm increases, so that, with the decreased contact between the rigid support and the cantilever arm, there is a change in the cantilever arm support location and a lengthening the cantilever arm beam. In this way, the contact and pressure between wiper blade and the windshield being cleaned is maintained constant or substantially constant as the wiper blade sweeps across the windshield.