I treated my GS to a 12K service+carb tune and a new set of Michelin Pilot Activs a couple of days ago. I've since noticed that there is a vibration through the bike and bars plus a whining noise when slowing at about between 40 and 20kms. It feels and sounds like my tyres turn into knobbies, particularly on a smooth surface. The noise sometimes goes in and out if I swerve the bike at the particular speed, only being apparent when the bike is vertical. I rang the dealer and they said the tyres need to be broken in and if it hasn't cleared up within a week to bring the bike back to have the tyres re-balanced. Is it normal for new tyres to behave in this manner? Any input much appreciated. On a side note the bike otherwise now feels and performs fantastic, it's like riding a new bike.