I am replacing a bent crankset on my 'O4 enduro with a Saint M-800 crankset. The specs indicate that the Saint crank works with Shimano Chain CN-7701 which I understand is a narrow HG 9-speed chain. However the chain I have is an HG73 which worked with my old cranks and old cassette (CS-HG50-9). What is the difference in these chains. I am planning on replacing the chain but I wasn't sure whcih one to buy and if all three of these are compatible? Anybody understand the difference in the chains? Thanks for your help.