The 2013 frame design by Corey Ireland addressed issues with the 2012 frame by reducing the model weight by 7% to 26kg, improving visibility, and ensuring compliance with new regulations regarding leg room. Key changes included lowering various frame components by 1-2 inches to improve visibility, removing unnecessary tubes to reduce weight, extending other tubes by 1 inch for added length, and targeting the reduction of the heaviest red and yellow tubes. These changes resulted in a frame that met the goals of reducing weight while improving visibility and regulatory compliance.