I think youll find, only a fool would change just a chain in the case where your replacing because its worn, as the sprockets would be just as worn and bugger up the new chain within a thousand miles!
If your changing for looks or cosmetic then you could get away with a chain on its own. But as they come in certain oversize lengths, it is an opportunity to fit a larger rear sprocket, as most find this beneficial!
Unless your regularly on your sports tourer at 170mph?
