The frames of other motorcycles are formed by pouring molten metal into a mold of sand and clay. Buell engineers instead developed a water-soluble bonding agent to use in place of clay. The new formulation allows them to start rinsing the mold away right after the aluminum is poured, rather than waiting for the cast to solidify and then breaking the mold. Water cools the alloy faster and in a controlled manner, preventing cavities from forming, which can weaken the structure. Buell used the method to produce a stronger rear frame that requires one less pound of metal.