Originally Posted by
Duragrouch
(above) My Cannondale racer circa 1989 has a lifetime warranty, I'm sure necessary, given the reputation of aluminum having a worse fatigue life than steel. Of course, it depends on how it is designed. Subsequent Cannondale frames got so thin in wall thickness, you could elastically move the surface by pushing with your thumb. They held up, but that was getting a bit thin for me. Any new material or process, will probably require a warranty for public acceptance, unless only racing use.
Trek offered a lifetime warranty on their (steel) frames from the mid-'70's, at least five years before Cannondale began marketing their bikes. By the time Cannondale bikes came along, such warranties were standard practice for major manufacturers selling in the American market.
I've always been dubious about the claim that thin tubes yield to thumb pressure, ever since I first heard that claim in the 1970's, when it was said of Reynolds 753 top tubes. Pinching the top of the coffee table in front of me, I can imagine that I can feel the wood compressing, but it's obviously just the flesh in my thumb doing the compressing.
In fact, I just checked the top tubes of two of my bikes: a mid-'60's Reynolds 531 Peugeot and a top-of-the-line extremely light aluminum Fuji from around 2005. From what I can tell, either they both flex from thumb pressure, or neither does. Though I imagine that I might think I felt a difference if I were already convinced there must be one.