Looking at post 7, the chain is not worn enough to create the wear shown in the picture. The spec for a new 520 chain measured between 11 rollers is 5.85", and he had 5.88", which is barely 0.5% longer than specification. Yamaha's wear tolerance is 2% (5.97"), and I use 1.5% (5.93") as my personal limit. The wear shown is not so much "wear" as it is peened, as if the metal had been to soft and yielded under pressure. Frankly, that isn't excusable, given that even my OEM Sunstar sprockets did't do that. Finding fault where it lies is not bashing.