Carbon fiber is magical stuff. Want it ultra stiff and strong on these axes, but super compliant on other axes? No problem. I used to follow Craig Calfee's CF bike repair blog a long time ago. Some legendary crashes and the CF turned out to be fine.

For me, it's all about the failure mode. If you don't know what to look for (and I don't trust myself nor think that I do), CF failure can be a real day-wrecker. This is a mental block I have, compounded by being a reteogrouch curmudgeon.

That said, out of all of the crashes that Calfee reviewed, one in particular stands out. A car blew through a stop sign and the cyclist hit the car. The front wheel was destroyed, handlebars broke, an aluminum crankarm broke, rear wheel didn't impact anything but was taco'd from sheer acceleration. Fork was fine, frame was fine (Trek Madone, I think?). Holy hell.

So while I have an admittedly irrational aversion to carbon fiber, I know from an evidence-based perspective that it's an amazing material. From a trustworthy manufacturer, CF is the holy grail of materials. What's even more surprising is that manufacturers are achieving these results with standard modulous fiber. There are much better grades of CF, typically reserved for aerospace and military, that would allow for mythically light builds.