Hard to adjust the back because putting weight on the seat part causes the back to spring forward.
Update: after a few weeks these chairs are so bad I'm going to throw them out.   Beyond disappointed at the quality.  The hinges are rusting like crazy and every time it rains the rust drips and stains the concrete and everything around, making a big mess.  The frame is heavy painted steel when I had been looking for aluminum (which I couldn't find).   They were way too expensive considering these quality issues.  This purchase was a major mistake.