Chandne

Like I said, the carbon fiber does not seem to break down but the resins do...the resins that are the glue, essentially. Now, I do not work with carbon but am close to the composites made for the aerospace industry (by hexcel, for example). In the bike industry, they use similar composites but often much more resin. The resin can break down over time (and with heat). Bikes may take way too long to notice and maybe you never will in most cases. Ti is probably still the king if welded very well. Now the alloy thing is also from personal experience with some softer alloy rims that were great at first but eventually after a couple of years, started to feel a bit softer and needed more truing. I did not examine the alloy at a molecular level, obviously. When I called Notubes, they said that the lighter rims would break down and soften up over time and to stick with the Flows or stiff carbon rims. My wheelbuilder (who may have read the same "soft alloy" discussions) said basically the same think. What happens from a crystalline structure level is obvious in metals when you heat and bend them but in rims over time/beating...does the crystalline structure slowly change too? Good debate and discussion. Fine...let's keep the alma mater out. It made me no smarter, though my dad's lessons probably was more of a nourishing mother.