If you want a rack for 4 bikes that won't be super sketchy and shake and whatnot, you need something a bit nicer. I highly recommend Kuat racks. I have expensive taste in general, but I am not putting my Trek Domane SLR 8 on just any crap rack. (I spent like $7k on my bike, which yes.. is nuts, but I love the damn thing). With the Kuat, Nothing to scratch it. Rock solid, built in decent locks and doesn't shake with the hitch tightening knob thing it has. It does stick out a lot, but it folds up nice.