VTBike wrote:Understandable why you might think this, but far from the truth. The carbon layup in cranks is much thicker than a frame. The function and placement of a crank is unique, and crank makers are smart enough to design for this. I think it's going to be quite difficult for you to hit any carbon crank hard enough to crack it - especially on a road bike. I also have carbon cranks on my MTB, and have hit them pretty dang hard. They mark up, even chip.. but nothing serious enough to cause serious damage.
I'll second this. I rode an FSA SL-k BB30 (5 arm version previous to current version) on a cross bike that got the tips of the arms banged and chipped. I expected it to break but it kept on going. I eventually took it off to replace it with a Red BB30 and it was only 70 grams heavier.