google is ur friend. Magnalium , alloy of aluminum and 5-50% magnesium. Although aluminum is weak and soft in the elemental state, aluminum alloyed with magnesium, manganese, zinc, tin, and zirconium to produce alloys useful in engineering materials. The strength and hardness of aluminum increases when it is alloyed with such substances as magnesium, manganese, nickel, chromium, zinc, iron, copper, and silicon. Magnalium lighter and more workable than aluminum is used in making metal mirrors and scientific instruments. guess it cant be that good for a bike frame :<