Originally Posted by avconnect
It is not the sprocket we are concerned about in terms of wear. The 13t sprocket causes the chain to wear and rub more on the swing arm pivot where there is a plastic wear block. That slide or wear block appears to be rapidly wearing such that the chain may soon cut through and start damaging the swing arm.
I see. It appears the chain will rub more, it will be one of those things you just have to keep an eye on. Acerbis makes replacements that aren't to expensive, or order stock parts. As long as you replace the guides when they wear down you should be fine. I usually order and keep high wear items like that on hand just incase.