Interestingly enough, most tensile strength ratings of motorcycle chains are either bogus or misleading. If there is not a DIN, ANSI, ISO, or Nippon standard listed next to a chains tensile strength rating on the package, then it's a safe bet the tensile number listed doesn't mean much.
I have heard a bunch of folks on Planet Sand complain about Sidewinder, but I can't remember why. Personally, I have never seen a Sidewinder product fail under normal usage. Most of the NHRA top fuel drag bikes boys runs Sidewinder products (I am not sure if it's a sponsorship deal) without any problems. With that said, I am a fan of DID, R&K, and Regina. I have used their chains without any problems. So far, front sprockets I have found the Renthal sprockets to be my favorite and for rear sprockets I still have not found anyone I like enough to use their product evclusively. :geek: