I’ve always felt the same as the OP about Clif bars. They don’t digest for me. For years I relied on traditional powerbars on my rides of 3-10+ hours but they are hard/impossible to get now so I had to find something else. At this point I’m eating the Hammer energy bars and they work well. A bit pricy, though, and I’ve never seen them in a convenience store or other stop on the road.