The choice of material directly impacts the bike's weight, durability, and handling. Chromoly Steel (4130) is the industry standard for high-end frames due to its excellent strength-to-weight ratio and flex characteristics, which help absorb impacts. Aluminum Alloy (6061 or 7005) is preferred for racing as it is lighter and stiffer, providing better power transfer, though it can be more prone to fatigue over time. For professional-grade competition, ensure the frame uses T6 heat treatment to maximize structural integrity.