cush drive rubbers

[gadget]

Hi all, just been cleaning the f2 (again) and noticed that when holding the rear sprocket (bike on centre stand) i can still rotate the wheel a little , probably about an inch or so. Am i right in thinking it's worn cush rubbers? or could i be missing something else? It rides spot on in all other respects except when taking up drive, i can feel clonk!! a split second before it moves.
Thanks in advance guys for any advice/info:

[gadget]

Aha, just as i suspected watson ;D many thanks gaz, good to get a second opinion before setting about it.
cheers m8