If I were to worry about the touring strength of any part of modern CF (carbon fiber) road bikes, it would be the wheels, not the frame. (You can definitely get great wheels built, but the stock ones often are not durable.) I always do my research before buying anything more major than a box of cereal (maybe a slight exaggeration, but you get the point) and that includes my CF bike, which had to last a lot longer than my nice steel one did (and already has). One thing I found was that there are quite a few 350-pounders on CF on the bike forums, and oodles of 240-pounders with tens of thousands of miles on their CF bikes, all without problems, in spite of crashes. The things that make CF fail are different from what makes the metals fail, but in general, CF is a lot stronger and more durable than the metals. Last August, our son, going 25mph on his CF Trek, T-boned a car that turned left in front of him without yielding. He flew over the car and broke his collar bone and nose in the landing. The force of the impact even deformed the front hub so it could not be re-used for a wheel re-build, and the dropouts were damaged; but according to Calfee's inspection and tests, there was no damage to the CF itself. He has put a lot of miles on the same bike since then, but with several components replaced. I would say just don't clamp to the CF itself; but clamping to the dropouts or to a metal seat post, I don't think you need to worry about anything.