Hi
I would like to know how do you like this concept shot?
looks almost real to me :), perfection of it reveals that it is not real 
My initial impression is that the lighting is off. With the backlighting I would expect to see less detail in the bike on the shadowed side. I would consider changing the direction of the light since I know you don’t want to eliminate detail in the bike but you also want to convey realism.
