Hi all. With temps below 20 degrees, I have time to ponder my bike...Hence this question that has long nagged at me.
I use a Park CC2 chain checker tool, which measures wear between the rollers: http://www.parktool.com/products/det...at=5&item=CC-2
Even if I use the chain almost until the checker reads 1% (=replace), I still have no perceptible chain stretch as ascertained by the ruler method (measuring twelve links).
So here's the question: do the rollers wear from constant contact with the teeth on chainrings and cogs, even without the chain "stretching"? In other words, if these two measurement methods give different results, which should I use? I'd hate to replace chains more frequently than necessary, but would also hate to wear out cassettes more frequently than necessary, too.