Originally Posted by
Lombard
As far as I know, carbon does not deteriorate with age or for that matter mileage
You could literally google composite fatigue and find out that it's wrong in two minutes - it deteriorates with (sometimes) age and particularly mileage.
I mean, seriously, folks, a cyclist climbing out of the saddle is a much more torquey machine than a typical motorcycle and the forces have a sideways and twisting component and are more choppy then a typical engine. Just climbing out of the saddle at a moderate 350W and 50 rpm is 66Nm of torque. How heavy is a motorcycle frame? A composite bike frame is 800 to 1100 grams, a quality metal one is 1500 to 1800 grams, of course they're all going to die to fatigue with enough miles.
Yesterday we were climbing a mountain and at the foot of the climb one of the riders had his old CF frame die, crack at the chainstay. It happens.