Originally Posted by
79pmooney
Is this the chain that came on the bike when you got it? If so, I'd just say stuff happens. You have no idea what kind of a life it lived.
Thanks Ben. Yes, you're right. And from what I do know of the history of the bike, saying it was well-used would be an understatement.
Originally Posted by
79pmooney
This just looks like a link that was pushed too far in when the chain was re-riveted. You (your wife) "bent" the chain using off-chainline gears. This pushed the outer plates out a touch and the plate on the far side slipped off the now too-short protrusion. You can simply pull out your tool and push that plate back on, then carefully center the pin and the chain will be ready to go. (I'd go with a new PC-1 if simply for the reason that this is your wife's bike. Infinitely small chance of failure vs catastrophic results-marriage? Not worth the risks.
)
Riveting chains of 9-speed or above is a no-no because the pins are peened and the flare from the peening will damage the hole in the plate when it is drive through. Plate is still plenty strong but the snug fit is no longer there, hence a quick-link of some type with a positive locking mechanism. But with 6-7-8 speed and below the pins are just simple,. clean cylinders and barely affect the snug fit when driven and redriven. (Do look carefully at both outer plates if you decide to re-use this. If you see no distortion they should be fine.) Chain manufacturers include quick-links now with all chains because we expect it and to protect themselves from klutzes. 35 years ago, the same chains came without.
Ben
As wanted to shorten the chain anyway, I removed the spread link altogether and closed the chain again for now. We'll take it for a (long and flat) test ride tomorrow, but I'll bring along a new one, just for piece of mind. I've ordered a KMC X101, that I will mount next week, and if that fits, it will be the chain to go with for the upcoming Eroica rides.
WRT the extreme off-chainline combinations: I did use them on the stand and some short test rides up and down the street to dial-in the derailleurs and make sure nothing would go wrong, but mrs non-fixie is getting better at understanding how these things work, so the big-big and small-small combinations are getting less use each season.
It does raise the question of the width of a four-speed block. As they were apparently used with 1/8" chains, I can't imagine they would be much narrower that a five-speed's 24mm.