I've been using sram pc-48s for a while now but it seems they are always already out to the 0.5 mark on the park tool when I first install them. It's only a short few months before they are getting past the 0.75mm mark and needing replacement. Is my tool miscalibrated or is this just normal? I'd like to find a chain that I could get some more miles out of. Is the pc7 a big improvement and is it 3/32" wide? What about the pc-58? I always assumed the difference in the pc48/58/68 was cosmetic and rustproofing. Is this wrong? How about rohloff chains? What is going to be the most wear resistant? Tired of replacing chains and driveline parts many times a year! Singlespeeding is supposed to be about minimal maintenance...