On my 04 Vulcan Classic, when I ride alone the chain is quiet, and I don't really hear any noise, I have adjusted the chain, it seems to have enough slack, but not too much. When I ride with my wife on the back the chain is very noisy at the front sprocket while accelerating or cruising, but if I coast it just clicks slightly. Is this normal? Our combined weight is approx 375. The bike is just noisier all around with both of us.