My four month old 790 has developed a strange front end (l think) noise. It’s a clicking/knocking sound that is most like the noise you get in a car when a pebble sticks in the wheel tread. It’s definitely speed related and not rpm related. I’ve checked both tyres several times and it only occurs at dead ahead (even a very slight lean angle stops the noise). Not a really big deal but v annoying. Your thoughts please ??