I do alot of ridding in the rain. at least I used to when it did rain. I found that when it comes to chains and derailers the best thing to do is clean and lube them after every ride in the rain. If not they start to build up rust causing them to wear out faster. It does become a pain in the butt if it rains all the time. If you do not have the time to clean them each time at least give the chain a good coat of lube but first dry the chain.