... steel 3 / 4, is half the weight of titanium, carbon fiber, like whole, and heavy use of lighter magnesium alloy ... magnesium alloys, but the disadvantage is the lack of carbon-fiber plastic, carbon fiber chassis so easy to damage because of fatigue fracture ... plasticity, avoid sudden security incidents, and the absence of such carbon fiber frame deficiencies. "Magnesium alloy", 6-10 times more shock ...