[mangoandmimi]

The setup itself is generally fine, however that doesn't mean it'll work for every hamster. If he's so nervous I'd start by adding more cover, so perhaps another shelf. I suppose the fact there's bars all around leaves it quite open too, so maybe adding something like hemp mats round one corner could help. My robo used to be in a Barney and I'm quite sure the bars made her more nervous around the cage, it leaves them more open really. So I added a layer of cardboard on the outside of the back bars and I think the solid wall helped.

The Barney is also quite tall which is a good thing for Syrians really, but I'd also get some hanging items. Those grass hammocks are supposed to be good but not used them in a long time. Sputniks too maybe. Again, things like this just make them feel more protected and less exposed from above.