Originally Posted by fbagatelleblack

I have never seen a Cannondale frame fail due to fatigue. Cannondales are very stiff, and they have plenty of safety factor built in. These factors minimize the impact of cyclic frame flexing in terms of causing fatigue over time, because fatigue is influenced by how much aluminum flexes, not just how many times it flexes. I am 250lb, and I hammered the heck out of my 1986 63cm Cannondale for ~20 years. The only reason I stopped riding it was that I went to bigger frames to make my aging body happy. The old C'dale is still hanging in my garage, as strong and stiff as it was the day I bought it. Granted, my first-generation C'dale frame is even more resistant to fatigue than a 3.0 frame, but the 3.0 frames are plenty over-built as well. They should last many, many tens-of-thousands of miles.

Yes, aluminum will fatigue over time with repeated flexing, BUT a good frame designer can push the number of cycles out into the BILLIONS before the frame fatigues significantly. Note the importance of the word "good" in that sentence. Cannondales will last a lot longer than say, old aluminum Alans or Vitus/Bador frames (or even the old, glued Treks).

- FBB