I've noticed that when riding on rougher/bumpier sections of trail, my chain will often bounce around a lot. It doesn't jump to other gears on its own, but it make a heck of a racket. I'm pretty sure it's hitting the chainstay, since it's more noticeable when I use the smallest chain ring up front. Is this normal, or a sign of that the chain is too slack? Would a chainstay protector help reduce the noise?