Chain size/speed

[Seamab]

How can you tell what speed a chain is designed for?

I've just bought a secondhand tandem (an old Roberts touring one) which has an extra set of cranks designed for small children which attaches to the stoker (rear) seattube. The small chain for the child cranks attaches vertically down to an inner chainring on the left hand side of the stokers cranks(the pilots chain attaches to the outer chainring).

So it doesn't have a cassette as such. I adjusted the child cranks down the seatube a bit and need to shorten the chain and thought i'd use a KMC link. I've only got a 10 speed link and can't get it to pull closed - it must be slightly too wide. What speed link do i need? The chain is a Sachs make and may be the original.

I hope some of this makes sense!

 

[02GF74]

1. helps if you know make/model of the chain.
2. 10 speed chains are relativley new, appeared maybe in last 2 years so and old tandem, unless it belonged to a time lord, is unlikely to use a 10 speed chain?
3. measure the width of the chain using claipers then work out how many speeds it is for and buy appropritate link.
4. otherwise buy 9 and 8 speed links and see which of t he two is the better fit. my money is on the 8 speed link.
5. or take the chain to a shop and ask the highly trained and super knowledgeble staff which link you sould use.