It is very difficult to judge these very small photos. Usually a photo included in a post to GG is best at about 575 pixels high. That way it will fill the screen on a 1024x768 resolution browser which makes up about 60% of the viewing world. You may be limited by Model Mayhem, and if so, you might want to look in to a basic hosting service or the space your ISP gives you to be able to post larger images that can be more adequately evaluated.
Just from what I can see of the photo, the bike handlebars seem to compete a little too much in the background and stick out at odd angles around the arms. I don't care for the photographer cropping off the top of your head as it serves no purpose. The whole photo has a slight magenta cast.
Model is Candace. I chopped off the top of the head, but for a purpose to make it look like only a portion of a photo as part of a composite illustration. When the model is looking at the camera, I usually find that chopping off top of the head doesn't sell as well. When looking away, and with other compositional elements it seem to work okay.