Originally Posted by DevTrammel
I've looked everywhere on the internet and I cant find anything on this. Fully stock with only 5000 miles on my bike, the bike runs kind of rough because it is very sticky. Chain slack is up to standards but the chain on top sags just enough to touch the plastic guard under it. This is picking up some plastic which is gouged out by the chain. Do I need a new sprocket? Maybe just a good cleaning? The only reason I can think I would need a new sprocket is because I often do freeway travel and the bike sees high rpms. I can post a few pictures if needed. Thank you for reading.
You may find from time to time that the swingarm and chain will flex enough so that the chain will hit the chain guide, especially with stock sprockets. If you want to reduce your rpms for hwy riding, consider a 15 tooth front sprocket and a 43 tooth rear. This combo will provide a good balance of acceleration and cruising speeds. Also the extra little bit in diameter of the 15t front sprocket will move the chain away from the chain guide and reduce the rubbing a bit.
Normally you'd want to change your chain with new sprockets, but with so little miles on your stock ones you should be ok not changing them. The most important thing is the make sure your chain gets cleaned real well, lubed, and adjusted properly for your model year.