Yes and no.


It's the quality of the materials and the quality of the build that determines the quality of the bike, just like any other frame material. But a well made composite bike will be around and ride-able longer than any metal frame bike, especially aluminum. All composite manufacturers (one of which I worked for) add UV stabilizers to the resin to prevent or significantly slow UV degradation. Although in practice with any frame material, a well cared for, maintained and properly repaired bike frame will outlast any human owner, which kinda makes these comparisons academic.


I think that composite bike frames get a bad reputation because people don't understand the properties and limitations of the material and that anyone who has ever fiber-glassed a car or boat repair feels like they can build or repair a composite bike. That is just not true. Composite bikes are (with certain limitations) stronger, easier to repair, and longer lasting. Now, I could walk up to your composite bike and stomp on a chain stay and break it. That's because the chain stay wasn't designed to resist forces in that direction. That doesn't mean it is fragile. Just like the composite air frame of a Lear jet can be expected to last for decades and millions of miles but an accidental bump or wing strike can easily cause damage.


I see a lot of posts about composite bikes just failing with no warning. While I am sure that has happened, just like with any frame material, any damage suffered by the frame that would lead to catastrophic failure is almost always visible and easily detectable at the surface. Also, a bike that has been in an accident can be inspected by a competent person with sonographic, IR tor any number of NDT technologies