One of my roadie mates had a set of carbon bars snap on him whilst whizzing down some steep bumpy road. How he stayed on I'll never know. He did replace the bar and stem - with more carbon. Both his and my road bikes are full "dino-dust" but for some reason I've never felt comfortable using carbon on a MTB. To be fair though, that's just me. I'm sure the product liability lawyers of US companies like Cannondale would have had something to say about it if there really were an issue. Plus, the Boardman bikes have carbon frames and I've not heard of there being any adverse comments. Carbon handlebars do seem fairly expensive compared to their ally counterparts though, and you can imagine why. Easton's EA70 bar is half the price of their EC90 (carbon). To be fair though, CC's price for a carbon-ally hybrid bar seems to be similar to the EA70.