Originally Posted by
ShannonM
The drivetrain was insulted and in terror of being replaced, so it threw a tantrum.
More seriously, 9-speed and above chains are often noisy on 8-speed and below drivetrains. My rule has always been to use speed-specific chains on 9 and above, and 8-speed chains on 8 and below.
--Shannon
Funnily enough, when using modern chains designed for indexed shifting systems, the chain for 6, 7 and 8 speed are the same. So if you are using an 8 speed chain on a 7 speed drivetrain, you are actually using a 7 speed chain without knowing it!
I've never tried, but I suspect using a chain built for fewer speeds than the cassette (like an 8 speed chain on a 10 speed cassette), the wider chain will always be clattering against the gears it is not in. I am currently using a 9 sp. chain and cassette with a 10 sp. front derailleur, and it seems like the chain wants to rub the derailleur unless I am very careful with the position of the shifter.