8 speed chain with 9 speed Campag cassette?

[RecordAceFromNew]

Hi I have searched far and wide looking for personal experience in using 8 speed chains on 9 speed cassettes, but found very few references, except the general view (e.g. Sheldon's) that "As you go to more sprockets on the cassette, you need a narrower chain".

I am using friction shift, so indexing/mechs/shifters are unlikely to be issues.

In particular the cassette is going to be Campag, which I believe is far more likely to work because Campag 9 speed has wider sprocket pitch than Shimano's (4.55mm vs 4.34mm).

I think it should work because the width of an 8 speed chain/pin is typically 7.1mm while it is typically 6.7mm for 9 speed (e.g. Sram). My observation is that if a 6.7mm wide 9 speed chain definitely works with the 4.34mm sprocket pitch for a Shimano 9 speed cassette, why wouldn't a 7.1mm wide 8 speed chain works just as well with the 4.55mm sprocket pitch for a Campag 9 speed cassette (since the "gap" for the chain to sit is twice the sprocket pitch minus sprocket thickness, and Campag 9 speed sprockets are also marginally thinner than Shimano's)?

I know one might wonder why bother? If it definitely/generally works, the flexibility it offers for swapping wheels/spares has to be a real bonus.

All personal experience/observation/suggestion appreciated!

 

[RecordAceFromNew]

I just have had the opportunity to try it. It worked with no noise, rubbing or any drama evident under use. The gears changed as smoothly and quietly as usual. I was using a SRAM PC48 chain on a Campag Veloce 9 speed cassette.

However, if I use my hand to push the chain against a sprocket on the cassette, the chain misses rubbing against the next sprocket by only a hair because the chain roller spacing is wider than the sprocket is thick. Hence while I would be happy to use an 8 speed chain with a 9 speed Campag cassette when necessary, I am not sure if I would recommend using it regularly.

 

[Steve Austin]

Sometimes things like that work. They're not supposed to and it won't work right all the time but for while and when needs must it'll do.