Why did it take so long for headtube angles to become more slack?
I think the pace of innovation in mountain biking has truly been astounding but at the same time, I am amazed that it took until about 2016 for head tube angles to slacken out. What was going on with bikes in the 2000-15 range? Was anybody trying slacker tube angles during this time? Were they not positively reviewed? Was it because bikes during this time were heavily influenced by cross-country racing geometry? Was it because of limitations in how stiff they could make suspension forks? Even a 2015 stumpjumper has a 68° head angle.