do you always have to replace the cassette when replacing the chain?

[Strelok]

even if you monitor it regularly with a chain checker and change it out just before the checker fits all the way in?

 

[alienator]

Originally Posted by Strelok .

even if you monitor it regularly with a chain checker and change it out just before the checker fits all the way in?

No you don't have to change the cassette with the chain. The cassette should last much longer than the chain, two chains, or maybe more. There are online sources that show what to look for on the cassette. Google will find such places. Running a chain that is way past its time to change can ruin a cassette quickly.