I've been riding carbon for 20 years, starting with the earliest Trek OCLV 5000 series frame. It's still going strong under a friend of mine. My next carbon frame a Trek 5500 was retired when the aluminium bottom bracket shell became un-bonded. Not really a failure of the carbon, though. The 5-year-old replacement BMC Pro machine is still going fine, and my new C59 is flawless.
In contrast, I have had two steel frames fail through fatigue. One, the head-tube at the lug edge and the other a steel steerer tube cracked through. These were both decent frames/forks. Until they broke.
In contrast, I have had two steel frames fail through fatigue. One, the head-tube at the lug edge and the other a steel steerer tube cracked through. These were both decent frames/forks. Until they broke.