My Park Tool CC-4 chain checker lied to me and I'm done trusting the 0.5 percent rule
I grabbed a used CC-4 off a guy in Bellingham for $20 and it told me my chain was toast at 0.5 percent wear, so I swapped it out. Two weeks later the new chain started skipping on the 11 and 13 tooth cogs, and when I dropped a ruler on it the old chain was barely past 0.75 percent over 12 links. Turns out the CC-4 measures differently than the CC-2 and I was throwing away perfectly good chains for no reason. Has anyone else noticed their chain checker reading way higher than the ruler method, or am I measuring wrong?