Originally Posted by
szasz
The tooth marked with the red circle is thicker than the other, and the inner link is too narrow to fit onto it. That’s why it’s not possible to put the chain on incorrectly, it always aligns with the correct link.
Yeah that’s a wide tooth. You said “
This thickness prevents the chain's inner plates from fully seating onto the narrow teeth.”
And this photo shows clearly that the inner plates were at least at some point lined up on the wide teeth. Unless this was only ever the case when it was not being ridden?
I agree this should be possible all round the circumference of the ring as per grumpus’ comment about the increased diameter with the chain riding up.
All of that said, the damage at the bottom of the valleys is still a mystery to me. Maybe the links could pivot that much…