If you did sustain head injuries, the other driver may say that you contributed to them, whether or not there is a helmet law. The reason is that there is overwhelming evidence of a helmet’s effectiveness and the fact that you did not wear a helmet tends to suggest that you were acting irresponsibly and should therefore bear some liability for the injury. At that point, expect ongoing negotiations about the degree your own negligence (fault) contributed to your injuries. Your damages would be reduced by your percentage of fault.

This could be very subjective, and here’s where you want an experienced negotiator on your team. Luckily, just as there may be a perception that you were careless, there is also a general public perception that SUV drivers are not sufficiently aware of people in less protected or smaller vehicles. So a much greater percentage of fault may go to the SUV driver.