Originally Posted by
Jeff Neese
Not true. Chains are the same with 6/7/8 speed drivetrains. I use Shimano HG71 chains on every one of my bikes and it's even labeled that way, as are most other "8 speed" chains. All of my bikes are either 6, 7, or 8 speed and I like that I can use the same chain on all of them.
That was not the case when the OPs bike was made, and he said it hasn't had any real service.
Again, original 6 speed chains don't work on 7.