It was caused by the center gusset being compromised by the crack. I made a picture to help explain better. I apologize, I may have been able to express this more clearly. This specific incident was confirmed. The center gusset crack was present BEFORE the sharp corner crack - for a few months, actually. We have never seen an arm with a crack at that corner, and not a compromised gusset. I hope this clears things up.
Because it is much harder than it sounds. This is where people who see pictures, simply do not understand some of the reasons behind our design.
Example. Due to our latest design A-Arm....wheel clearance has been compromised now. At full lock, the odds of the wheel hitting the gusset are now much greater - especially when the customer has wide wheels up front...or inset wheels, etc.
Here is a picture of said example. This is a BMR/Griggs set-up road course car.....with the current version BMR A-Arms.
I assure you, we don't just throw stuff together and ship it. There are many reasons behind our decisions. No offense to anyone reading this - but, it is extremely easy for people to look at these occurrences on a computer, and feel that they know how to "do it" better. It is similar to when I watch my favorite football team playing on TV, and cuss Romo for being an idiot and not hitting an open receiver.
We are not perfect - no suspension company is. But instead of accepting our designs, we are ALWAYS looking for ways to improve them - regardless if the only issues are on race-cars, etc.
I meant what I stated previously - there is a very good reason that many companies have tried to make these pieces over the years, yet only 2 companies offer a version that is street-able (the other company, has a higher failure "rate" than ours, btw. Way higher..). They are a tough design to "perfect" based on the factory design and clearance issues.
Hope that helps.