Originally Posted by
Mondo734
SO, in sum the 8 speed chain would work fine for a 7 speed cassette but a 9 or 10 speed one would be to thin? Would a 10 speed chain work for a 9 speed cassette or vice versa?
You can use a thinner (higher speed) chain, but there's no point. Chains got narrower beginning with 9-, then 10-, etc.
That said, 8-speed and lower uses the same exact chain, so whether it's labeled as 7-speed or 8-speed, they're all 5/6/7/8-speed.