While not quite a crash bar - I've had the experience that my system works: Hand-guards that attach to the end of the handlebar AND (big and) CycleRacks rear rack. I've dropped my bike on the trail and because of the Cyclerack, it saved the back, and the hand guard saved the front (as well as my clutch/brake lever).
Good to hear on the cycle rack, have one coming from a member here. Will check out hand guards. Concerned as daughter will be most of the riding. Also will be installing hyperlites and visionx leds on front, as I have done on my Bonne. Can be seen better and the front leds aimed for spotting deer-critters. Still would like front guards though, maybe make up if I can't find.