DaveSSS 

Don't exclude the opposite situation, where a chain may show .25% elongation, even after 6000 miles of use, but the roller and side clearance wear is overly large. The roller wear at that point can still cause new-chain skip. A Campy chain can do this, which is probably why they suggest using calipers between the outer plates to a maximum length of 132.6mm, rather than measuring elongation alone. Over that short length most of the wear is roller wear.

I started monitoring the elongation on sram axs chains that I had in use that also seemed to elongate very little, but now I've got two bikes that need 55 inch chains, so my previous 54 inch chains can't be used and I'm starting over. I will not be using only one chain on each bike. I much prefer using several chains in a rotation.

I've read reports of axs users with 6000 miles on a chain that still checks OK, but those users don't monitor side clearance or roller wear. Most likely, their second axs chain will skip and their $350 cassette will have a very short life. I've also read of outer plates cracking after 3000 miles.

https://weightweenies.starbike.com/f...2596&mode=view