I'll echo that if there are bass suspended but no baitfish around, they are notoriously the hardest to catch. I would throw a few at them and if nothing in about 3 minutes would move on. As far as contact when cranking, this is the only way I ever get bit is by keeping constant bottom contact with my bait (except a lipless crank). I reel down until I touch bottom, then just slowly crawl it along the bottom with a sweeping motion, pause to reel up slack, then sweep again. Most hits come on the pause.