The rustic background distracts from the very interesting forms and textures that could have been explored and highlighted--especially the contrasted and complementary textures of the rusted metal and the concrete. Simpler would have been better in this case--much more striking and arresting. It feels more like a story, now, which distracts from the impact of some really interesting subject matter.
I really like the concept and tones. My only suggestion would have been to show more of the wheel, or to shoot at an angle where you can get the bottom and top of the wheel rather than the right and left of the wheel. However, I love the rust, colours, DOF, etc. - 8