Originally Posted by Portis
I'm not a small, light woman but I am a light man riding flat terrain. I only have 4000 miles on my road bike and I am on my 3rd chain and second cassette. I lube regularly and replace when chainwear indicator says so. I might add that i got new wheels this spring and just threw on a new chain and cassette to go along with the wheels.
That's your problem right there. The various "chain checkers" measure chain wear using a flawed concept and give very misleading results. Measure your chain carefully using an accurate ruler over a 12" (24 pin) distance. If the distance between 24 pin centers is less than 12-1/16" the chain is fine. If it's 12-1/16" to 12-1/8" replace the chain. If it's over 12-1/8" you will have to replace the cassette too and maybe sooner.
I'm a reasonably light (by current standards) 150 pound man who rides in very hilly terrain and my chains and cassettes routinely last 5000-7000 miles. I expect you are discarding perfectly useful chains and cassettes.