Originally Posted by
Timmi
Chains from 7spd and 8 speed are the same. same spacing, same cogs. the rear cluster is just wider, and the wheel not as good structurally as a result. 8speed is popular out of china no-name factories and is junk that should be avoided.
Having tried to use quality SRAM chains I had, on clusters that are designed for less gears than the chain is designed to be paired with, I can attest that most of the time, the chain won't even go down onto the cogs and won't seat itself properly.
Most of this is incorrect.
First, when Shimano and others went from 6/7-speed to 8+ speed, the rear dropout spacing was widened from 126 to 130 mm so the extra wheel dishing was insignificant and wheel strength and durability did not suffer at all. Are you really aware of a huge increase in wheel failures since the change, which happened over 25 years ago?
Second, we still don't know which freewheels you tried to use that 9-speed chain on but I'm currently using a 10-speed chain (even narrower than 9-speed) on an 8-speed cassette and it works perfectly.