Originally Posted by
Alcanbrad
As for when to replace the chain, the answer is before it wears out. Invest a few dollars in a chain wear measurement tool and check it (and all your chains).
Adjusting the eccentric is a matter of the specific design. Most have 4 (2 each side) locking set screws. Losen all 4 and use a pin spanner to rotate the eccentric to tighten the chain. I prefer to use a bottom bracket wrench to turn the eccentric but it only fits on 2 of my bikes.
Thanks. I already have a chain tool. It indicates .75. As I can get close to 5000km on my road bikes (with proper cleaning and lubrication) I am surprised with the wear of this chain on the non-drive side.