Originally Posted by
Carbonfiberboy
Here ya go:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829243/
and
https://www.limit-fatigue.com/limit-...-life-fatigue/
and
https://iopscience.iop.org/article/1...8/1/012017/pdf
I was under the impression that CF had no known fatigue limit, but that's because I was dealing with overbuilt structures which were designed for minimal flex. One assumes that quality CF bike frame manufacturers put strain gauges on their test frames when they hand them over to the test riders, so they're not just going by feel. The idea is that a good CF bike frame doesn't flex in such a way as to absorb power from the rider. When I got my CF frame in 2000, I noticed a huge difference in my ability to accelerate it compared with the 80s steel frames I had been riding, which felt like I could rip the bars off in a sprint. Otherwise known as stiffness. I would assume that a CF frame optimized for weight rather than stiffness would have a shorter service life. Obviously, pros look for a balance there. BTW, steel frames have a shorter fatigue life than CF if stressed similarly.
Fascinating stuff. It's interesting to think about this research and information from a non-pro perspective, where most of us likely aren't putting the kind of stress on a weight-optimized frame that a pro would, and in theory could extend the life of a CF frame longer. At the same time, perhaps even under normal person loads a lightweight frame would still degrade faster than a more overbuilt structure.