Whats the deal with bike manufacturers claiming that a heavier rider just needs a sturdier frame, when in reality, the entire design philosophy needs to be rethought from the ground up? I mean, its not just about slapping on some heavier gauge tubing and calling it a day. The increased weight and stress on the frame, wheels, and components requires a fundamental reevaluation of the bikes geometry, material selection, and structural integrity. So, what are the specific engineering challenges that manufacturers face when designing bikes for heavier riders, and how do they overcome them without sacrificing performance, efficiency, and safety? Is it really just a matter of scaling up existing designs, or are there more nuanced considerations at play?