Originally Posted by
user_1
I've read it's not good for the chain to open the link - any truth to that.
Modern riveted chains (used on clusters with more than eight sprockets) do not like to have pins reused once they have been pushed out to open the chain. Instead, they use a "master link" that can be repeatedly opened and closed:
The master link will look slightly different from the other links. Ideally, a "
master link pliers" is used to open the link, but a needle nose pliers, carefully applied, is often sufficient.
N.B. the width of the master link must match that of the chain to which it is attached, so a chain for a 9-sprocket cluster will use a "9-speed" master link.