The other night, after washing my bike, i was moving it around and noticed what sounds like a bit of a rattle inside the forks when I move the bike from side to side quickly. It's not really loud - you'd never hear it with the motor running. Sounds like it somewhere up near the upper half of the forks - around where the lower triple clamp is. Is this normal? I haven't noticed it in my other bikes. Just wondering if its always been like this and I've only just noticed it. What could it be?