Originally Posted by tophusaf
How long do these usally last? I was cleaning my bike after a ride and notice that some of the teeth look like they are starting to wear (sp). The ones I have are stock and I have owned the bike for 9 -10 years. I imagine its time to replace them but with what? Do you need to replace the derailleurs at the same time?
One thing that will make a big difference is how clean you keep the drive train. Cleanliness and longevity are most definitely tied to each other. People that are meticulous about keeping their chains and drivetrains clean can get some very high mileage out of them. But, if you ride in the rain regularly, or don't keep all the bits clean, you'll get less life. Rain introduces grit from the road into everything that gets wet on a bike. There's really nothing you can do about it, but, again, a regular washing helps a lot.
As with all things concerning the longevity of bike parts, YMMV.
Have your LBS check the cogs and chainrings for wear and if you replace them then replace the chain at the same time. It's probably a good idea to check the tension and jockey pulleys at the same time.