The builder of my Off-road tandem [Jeff Shuggs] has had some failures on his own bikes.. they were more of an overload type event vs fatigue though. I have one of their mountain bikes.. it is quite old now. I only use it as my winter trail bike now. but the beam seems fine. I did have one of their frames fail as has been stated, and I had two different vs. of their stems fail. One was a recalled stem that we did not get notified about. It almost killed me!!!
glenn