I am in the ball park for about 2000 miles per chain. daily commute through every kind of weather. takes its toll on the hardware. shifting is the first clue if I haven't checked the chain length lately.

wipe down the chain after rides, keep sprockets clean, wash the chain and it will help extend life of chain.

it's amazing how fast 2000 miles pops up when you ride alot. 20 weeks at 100 miles per week. zips right by.