Stock 17/39 is good for just highway stuff. Depending on what all of your riding consists of, you could even consider going a tooth larger on the front or a tooth smaller on the rear as well. 18/39 or 17/37 or something similar. Never done it personally, but those sprocket sizes should be available. And you definitely want to be wearing ear plugs while riding. Helps a lot drowing out the bad noises, but you can still hear plenty good.