About 4 weeks ago I installed a new SRAM PC-971 chain on my Surly LHT. This morning I've noticed that one of the outer chain link plates started to pull away (to spread in a way that the pin is not engaged with the outer plate). My previous chain had failed in exactly the same way, but it was 50% worn according to a chain stretch checker. While riding this bike on a daily basis for over 6 years, I've never had this happen before. Does anyone have any ideas of why the chain is repeatedly failing in this fashion?
- RD: Deore XT
- FD: Tiagra, triple;
- Cassette: SRAM 9-speed, 11-32t (reasonably worn, but not skipping yet);
- chainrings: original to the bike, reasonably worn, the teeth don't look terrible yet.