I agree with 'nun'. For a credit-card tour you should be able to fit everything into a saddlebag and/or handlebar bag and keep the weight down to about 10 extra pounds. That's insignificant in terms to extra stress on the bike - after all we don't go out and buy sturdier bikes just because we put on an extra 10 pounds over the holidays. A trailer would probably weigh 10 lbs. or more empty and makes sense if you're going to load it with 40+ lbs., but I wouldn't consider it for a lighter load.