Originally Posted by
KerryIrons
Over the decades lots of people have reported their chain checker showing 75% wear on a brand new chain. That sounds wrong to me.
I have seen a lot of people complain, as you did, that chain checkers show 25% "wear" right off the bat, but not 75%.
Some chain checkers may be out of spec. When I ran service departments I rounded up all the chain checkers and allowed only one model to be used, then checked all examples as behaving the same on several examples of worn and new chains. There is little chance that four Park CC 3.2 are all wrong and by exactly the same amount.
A home mechanic would be wise to check their tool against new chains as well.
Elongation alone may work fine - if the rollers hold up as well as the part of the chain that's being measured. If the rollers wear faster than the pins and links, then you're measuring the wrong thing.
The goal here is to replace your chain before it puts unnecessary wear on other components. I have yet to hear anyone complain that their chain checker caused them to replace their properly lubricated chain every 500 miles.