I don't think you've got enough paint on there to really get the chrome effect.
As I am sure you know when you spray paint stuff there is a progression from little dots of paint, connecting and over lapping up to a point where the surface becomes saturated and kind of glossy and even. If you add more paint at this time you get drips and over coverage. You want to get it to that glossy and even stage for the chrome effect to happen. It looks like you achieved it in some areas on the freame but not all, hence the drab silver look, not the wicked chrome you were going for.
Good luck, go slow, and buy more spray paint!