Knock when rolling on and off throttle

[Legsrgv]

Hi all, so I've put the original exhaust back on my busa, now whilst riding I notice a mock from around the front sprocket area when changing gear and rolling on and off the throttle, I've checked the rear sprocket and cush drives and they are ok, btw the chain is only a few hundred miles old, any advice greatly recieved

 

[Bumblebee]

Have you put the bike on a rear stand and rotated the back tire back and forth while in gear?

Have you checked the rubber chain slider on the swing arm to make sure it is not damaged and the chain is not hitting it?

 

[ottafish]

Chain tension?