This reminds me sorta of another portrait I commented on.... Pretty much everything I said there is true here (ironic if this ends up being the same photog lol). In addition, however, I'd like to see the bit of his head not chopped. I'd also consider bringing more of the motorcycle into the frame. It would strengthen things in regard to the "environmental portrait." I picture the shot being from low to the ground, looking up at the rider. Perhaps slightly backlit with fill light. I like everything about this except for the close crop.
Great portrait, but the vertical lines above his head, as well as clipping just the very top of his head, are a bit distracting. The light and focus are excellent.