I don't know yet. I can't help but notice that the same model is no longer shown on their website. One thing for sure, we will be checking spoke tension.
I rode my mountain bike on gravel yesterday, and had 2 km/h faster average speed than I normally do on the roads I used, and set a
PR on a hill. Yet it's a full 6 pounds heavier than my Bombtrack. My son, who sold me the Bombtrack, was on the ride and surmised that because of the metal fatigue, the rim was flexing and causing a loss of efficiency. Anyway he said he would check spoke tension for sure this time. You can also be sure I will be checking the rim periodically for signs of hairline cracks and fatigue before it fails catastrophically.
I could get another brand, but this has aroused my scientific curiosity and I'm willing to give it another try to see if spoke tension was the issue or just poor quality.