Originally Posted by
tomtomtom123
I have the Shimano tool and it's difficult to know when you're just at the borderline of the pass/fail because just a light push will make it go through.
I agree. That's why I like the Park tool, even though it doesn't compensate for roller wear and gives the "1%" reading a tad bit early. That's a good time to change the chain. If I ever *really* want the exact state of my chain, I have the steel ruler.