Ah, but what you're leaving out is what type of oil are you using? Are
you using regular old dino oil or synthetic oil? If its regular old
dino, then an oil and filter change every 3,000 miles may be prudent.
If you're using synthetic, than anything less than say 7500 miles is
probably too soon.

But getting back to bikes, the key with chains is to measure them for
"stretch". If its more than 12" long, replace it!