[FrattonEnder]

I've noticed something on my Zed with the wiper blades recently in that the contact area becomes variable in really odd places. Before anyone pipes up with 'change your blades', I did so only just before Christmas.
I've switched from metal framed blades to Bosch Aerotwin blades and initially they were perfect with a consistent sweep and no lift. However, the bottom end on the drivers side lifts and flexes at speeds above 30mph and the centre portion of the sweep under the connector is really patch. I can live with the wobbly trailing end but it's the centre section that bothers me. There's no obvious signs of any cracks in the plastic of the blade contruction that could cause flexing. I've cleaned the screen and the blade, so I'm taking a guess that possibly there's not enough pressure on the blade from the wiper arm spring. Does this sound plausible or am I better off going back to metal framed blades?