36 is stock...and it sucks. Definitely geared WAY too high (unless you are on a track with a really long straight). Don't personally know if the stock chain will take +2 on the rear, but likely it would. It will definitely take -1 up front, though (cheaper, easier and a bigger change than +2 rear). 525 is the width, not length, though, so that won't change. If you need more info on chains and their descriptions, I wrote something in the hall of wisdom forum a couple months back.