Quote Originally Posted by Krasi View Post
It's all nice with the o-ring (or even x-ring) chains, but power losses with them are higher which is noticeable with our small engines.
+1

Agree with this, however, you can convert sizes to help recover some of those losses. I documented this extensively in my XTR250 thread a couple years ago. A very high quality 428 O-Ring/X-Ring chain is a far superior alternative to the 520 crap chains that come on almost every Chinese motorcycle. There's no Chinese 250 that puts out enough power to worry about using 428.

Cheers!