Originally Posted by
Flandry
Ah, i looked at some 3/32 chains and they are calling them 6/7 speed chains. That makes more sense now. Thanks. So the internal (width) spacing on 6-speed chains will fit over gears also intended for 1/8 chains. It's the 8-10 speed chains that aren't compatible.
I think you have it backwards.
First, it's easiest to deal with single speed specific parts. You'll be able to find 3/32 and 1/8 chains from any LBS that are single speed specific, which removes the confusion of trying to figure out how many gears works out to what chain width.
Second, it's a 1/8th chain that works with either 3/32 or 1/8 drivetrains. A 3/32 chain will only work on 3/32 components. Basically, the chain can be bigger than the cog it goes on, the cog can't be bigger than the chain or the chain won't slip over it.
Originally Posted by
Flandry
So, that means that the 16 tooth freewheel in the singlespeed wheel should work with the chain on the 12 speed, and the cogs for the Alfine are all going to be narrow enough for either a 3/32 or 1/8 chain.
If you're talking about non single speed bikes, you need the chain that matches. A bigger chain will fit over the cog, but will probably get jammed between the next largest and smallest cog if it's too wide.