Timely thread for me. I was putting a TSDZ2 mid drive back on my Schwinn Hybrid bike for a few hundred miles of riding in eastern Oregon starting this coming weekend and this thread prompted me to check it for wear. KMC X8 chain used with and without the TSDZ2 on it, not sure of age or mileage but the bike is about 15 years old with thousands of miles on it and I recall this is the second chain ever on this bike. Chain wear gauge slipped in easily at both 0.75 and 1. Had enough time to order another chain to be delivered today. 11 speed chain on my Yamaha mid drive bike didn't show significant wear in couple thousand miles of riding when last checked.