Chris brought up some good points. I felt a need to elaborate on some of them.
I am an avid mountain biker. Some components, mainly handlebars and seatposts are made of carbon fiber to save weight, and improve stiffness (Some manufacturers make complete bicycle frames as well).
Chris pointed out that Carbon fiber is not as strong as fiberglass, but stiffer. Be aware that carbon fiber does not give any warning signs of impending failure. It looks just fine and all of the sudden it snaps in two.
If you put even a small scratch into a carbon fiber handlebar, there is a high probability that it could catastrophically fail, and possibly severely injure you.
Obviously on robots, you wont be severely injured if it fails, but there is likely to be lots of robot on robot contact. If you're constantly scuffing up carbon fiber that is used as a structural material, it is likely that it will fail.
Some things to keep in mind
Cory