This paper reviews advanced experimental design methods for use in evaluating multivariable effects related to load capacity degradation of fiber-reinforced composite recreational structures, such as bicycle frames, that may be subjected to subtle forms of small projectile impact damage. For instance, road debris impacts, caused by particles (that is, stones and pebbles) ejected from other road vehicles, can result in subtle damage to the primary composite frame structures and may lead to reduction in load capabilities and safety margins. To demonstrate the test methodology, multilayered composite tubes of varying diameter and thickness were subjected to high velocity gas gun pellet impacts in order to induce damage beneath surface layers that showed little evidence of severe impact. Bilateral eccentric column loading was then used to simulate strength degradation in normal use after projectile impact damage had been applied. The experimental design method utilizes an efficient number of test articles to examine the influence of many variables including material imperfections, manufacturing inconsistencies, and subtle impact damage. The test method combines the test data into a experimentally developed mathematical response function that identifies nonlinear interaction effects of several variables that cannot be ascertained easily by traditional single-variable test strategies and analytical approaches. A case study, dealing with an actual mountain bike frame failure, is also reviewed to demonstrate the practical need for development of fault-tolerant designs.