Originally Posted by HerrKaLeun

I always was a "metal ruler" guy to check chain wear because most traditional chain-checkers don't account for roller wear.

Besides Shimano and Pedro's now Park also has a proper chain checker. it always seemed hard to measure with the ruler exactly in a dark garage etc. Maybe a ruler in theory is more accurate, but it is quite hard to hold it to the same part of the pin at each end.

I finally broke down and bought this chain checker and I'm glad I did. it works really well and quickly.