I run the 35mm SKS P-35 Chromoplastics Longboards over 28mm tires in the three seasons. The 45mm ones go over my 35mm snow tires in winter. I like that the front longboard hangs to so close to the ground. The bike and I stay a whole lot cleaner.
FWIW, I've had exactly the opposite problem as TomCat_Ford. I could never get Cascadias to stop rattling, and the SKS are silent as a tomb.