Originally Posted by
realityinabox
Yesterday when I was cleaning my chain, ran the chain checker on a whim and was shocked to find that I was already dropping in on the 0.5 measurement. The 0.7 measure is still good, but I am still shocked that this chain has worn out so quickly.
Check out the specs for your chain/groupset. Some say that .5 is acceptable and .7 is when you should replace, others say .7 is acceptable and 1.0 is when you should replace. (I've seen the some chain checkers with .5 and .7 and others with .7 and 1.0)
You may not be as close as you think. But yes, a worn cassette will wear a new chain quite quickly.