I changed out my front sprocket at 11K miles, the rear has 17.5K on it now and still looks very good, almost no saw-tooth or engagement wear patterns on the teeth, though the old front sprocket was pretty gnarly. Chain was changed with the front sprocket and the adjustment hasn't changed since I double checked it at 13K, so chain stretch is not a major worry for me.. I don't beat on the bike, but lots of highway time at speed in excess of 90-100 should show some sort of wear, but nothing notable. I plan on a quick-change hub installation over the Winter, and will probably redo the chain and front gear at that time. For lube I use a 50-50 mixture of 90W140 and Red synthetic grease. Wipe the chain down and brush it with Xylene to clean it then wipe it dry, rub a coat of the mixture all over the outside and then a thick bead on the gear side, run it a few miles, wipe it off and done. I saw a video on making your own Paraffin wax application, and tried it, and it worked pretty well, was a lot cheaper per application than any spray-on mixture, and kept the chain a nice coated whitish color (the links are red to accent the bike...) but went back to the other formula because of its ease of application.