Originally Posted by ptempel

I'm at the point where I just replace the chain and cassette together. If it gets noisy or starts to skip in one or more gears, then its time. I also just lube the chain with air tool oil when it starts to look dry. That's been about once per week since I usually ride every weekday for cyclecommuting. Finally, I just wipe the chain after every ride. I don't bother with the cleaning tool that I used to use anymore. Seems to work ok so far.