I have a 2008 Classic with 14k miles on the clock. At around 1,500 to 2,000 revs but only when accelerating (and about to change gear), I hear a nasty loud rattling noise from the front and I feel some slight vibration in the handlebars. Sounds like it's coming from the radiator but I'm not 100% sure. Once I'm in fifth and on the open road, there is no noise or vibration. Doesn't happen when decelerating either. Should I "seal" the radiator cover with rubber shims or is this not advisable/unsafe?