This is something, the sworn bike expert Dirk Zedler from Ludwigsburg can totally agree with. (...) As far as carbon is concerned, Zedler is of the opinion that: "Bad products of negligent manufacturers or wrong usage can damage the reputation of a basically good material." Furthermore, he considers carbon not to be the material of choice for all kinds of bikes: "It does not make a lot of sense for trekking bikes which are left standig outside unobserved the whole day."
Interview:
DR: Mr Zedler, do you have more work now than before the carbon-frenzy set in?
DZ: Yes. There are drastically more damaged frames. Not necessarily due to accidents, but because of things which would normally be small problems but become really big ones with carbon frames.
DR: For example?
DZ: You lean you bike against something, it falls over. There would be a dent in an aluminium frame, a carbon one cracks - maybe invisibly. The people come here to be on the safe side.
(...)
DR: Which parts are especially sensitive and endangered?
DZ: Basically the weight-bearing parts are always critical: handlebars, seatpost, stem and fork. Our experience as expert testers is that you can make sensational parts out of carbon. But you can just as well produce parts which look the same, but are technically really bad. You should therefore only buy such parts from the most reputable source.
DR: Are the manufacturers careful enough when producing such parts?
DZ: There are considerable differences. You can make the best things out of carbon - or the worst. What is so crazy about it: Most carbon stuff is made in the same region in China. And there, manufacturer A has fantastic things produced while manufacturer B has really bad stuff made in the same company.
(...)
DR: Are there no legal requirements or standards for these products?
DZ: There are, but they only are minimum standards which apply for the European Union. And there are not exactly demanding.