Nuts, chains and sprockets.

[darrsi]

[quote author=darrsi link=topic=9329.msg95654#msg95654 date=1377076648]
[quote author=lds1973 link=topic=9329.msg95643#msg95643 date=1377072196]
I'd whip it off and remove sprocket, clean all with wire brush and refit with thread lock, torque to 80 and see how you get on. Or whilst its all off check the nut runs up the shaft.

He's already said it didn't feel tight at 90Nm.
[/quote]

Exactly. Something isn't right hence the need to inspect and clean. I wouldn't be riding around on possible cross threaded/ damaged thread etc etc. Would you?
[/quote]

Judging by the photo', the shaft thread looks more than ropey to me anyway.