Check your front wheel ballance weights are still on - good tread all over - no obvious "bubbles" or stones stuck in the tread line after this it gets down to real mechanical stuff that I have no idea about anything after filling the tank up and making sure I have a good set of tyres is beyond me but I'm sure the experts on here will tell you what to check for bearings head races and all that technical gubbins
And having checked out my front wheel recently looks like I need a new front tyre during this month as its wearing on the off side third more than the rest either way time to dig deep again