I am in the market for a new chain for my road bike. The current setup is 8-speed sora with an HG50 shimano chain. I was looking at getting a new one and got confused when I came across the variations - HG50, HG70, HG90, HG53, HG73, HG93 and then IG50, IG70 and IG90.
Can anyone tell me about compatibilities and what all these models are for? - I always thought 8 and 9 speed use the same width then 7 is a bit fatter and 10 is thinner???