When to replace chain?

[verner]

HI

I'm in the process of changing the bearings on my argo and am wondering how you determine when the chains need to be replaced?
Mine are very dirty, but are they still good?

Thanks.

[JohnF]

In the bicycle world it is considered time to replace chain when "stretch" has reached 1/16 inch over a foot.

If you use this standard, say with 5/8 inch pitch chain (#50), then if you stretch out your chain, set a rule center to some rivet and then if you measure that the rivet that should center at 15 inches has passed 15 5/64 inches, it is time to replace the chain.

The danger of using chain too long is that it will wear the sprockets. Worn sprockets will wear out new chain very fast, no matter where it is made.

Here is an article showing sprocket/chain wear.

[verner]

Thanks John !