just returned from a 1100 mile trip and noticed there was some rust on the chain, mostly on the outside of the links though a little on the sprocket as well. I removed it with kerosene and a rag with wd-40. I use dupont drywax lube but did not lube it during trip. is this normal or should I go back to an oil type product? maybe it just needed it more often than 1100 miles. no rain during trip.