Professional racing subjected suspension components to an ordeal by fire. Any part with a thoughtless stress riser would surely snap under the loads of 15x15 inch gum-ball-sticky racing tires. Each failure, whether on our own car or that of a competitor, taught everyone on every crew a lesson in structural design. The buzz in the pits was about the "tweak of the week" on a good day. Everyone was always trying figure out how quickly they could get and fit the latest mechanical improvement that showed up that weekend on a competitor's race car. On a bad day, when a mechanical failure sent a familiar driver off the road at hair-raising speed, the word about "what broke" spread quickly too.
Wheel studs on our D-7 snapped with unnerving frequency during the first half of the 1968 season. One day Jim Hall came by after we lost a wheel out on the track and he examined our studs. Hall was a keen engineer and showed us where a machined radius was probably too small, allowing stress to concentrate and fatigue the stud under repeated heavy loading.
Can-Am crews would parade past a crashed racer and ask to see the failed component. I recall learning many practical lessons about welding, machining, heat treating and graded hardware in the cauldron of those race weekends.
Chassis failures occurred from time to time and taught us all lessons too. What rivet patterns would securely fasten a suspension to a monocoque tub? Never apply suspension loads to a space frame tube in bending. Fabricated aluminum brackets must be heat-treated. Grade 8 bolts can be too brittle for certain applications; Grade 5's may prove stronger. Every mechanical DNF taught someone a lesson.