Originally Posted by
Juan el Boricua
Although it might sound dumb or odd, have you checked the quick release's tightness? Also, are your pedals one piece body or caged? The latter ones can sometimes make "noises". Have not much experience with cassettes, but I had a Shimano cs-hg51-8 that would "clunk" when powering on it; it had a smidget of play corrected with an aluminum shim between the gear cluster and lockring. Good luck!
Thanks for the reply. I will try tightening the quick releases tighter and see if that does the trick. My pedals are "cup and cone" design. The Dura Ace ones I suspect need more frequent adjustment than the equivalent Utlegra or 105 versions which use caged, sealed bearings from what I can tell.