Rubbish. It will only break if the loads exceed the ultimate strength of the material. 4mm thick carbon fiber is very strong, stonger than 4mm aluminium. As for the statement about carbon being not good at taking blows. This is a very much overstated anomoly with carbon fiber. It can be somewhat brittle however that is taken into account in the design and manufacture of products using carbon fiber. Just because its carbon does not mean its going to crumble if it takes a hit.