[Clippy]

...then you either have: -

1) Tight spots on the chain

or

2) A knackered circlip groove in your sprocket retaining flange.

Antonye has posted about this several times, so do a search on 'rear hub' or 'sproket flange' and all will be revealed!

I did the cush drives a month ago, and have just fitted the later type spocket flange as the clicking had continued - now all is quiet and as it should be in rear hub land!!!

Giles