The one on the bike I'm working on been sitting a while, should I run it until the kinks are out or measure it like it is? Cause I think right now it's shorter than it was new. The PB blaster lube doesn't seem to be helping at all.
Just teasing of course. I'm not good enough with records to help here. Comic relief?
Speaking of "shortening chains": this CAN happen! Here's how it does (it has happened to me twice)-
The chain develops a wear pattern in the pins and internal bearings early, like in the first 1000 miles. This becomes the cjhain's "Run Direction". If the chain is removed and reversed, the metal grit in the links starts to migrate out, and the other side starts to wear, but the grit does not have any place to go, really: so, it fills in the space between the pins and bushings. The biker usually swaps the chain direction unknowingly, and the chain adjustment is in the same places, when he reinstalls it (because we all used to take them off to clean them, then reinstall and lube). When the grit migration starts to occur, the looseness that was in the pins gets filled in with the grit, and the chain shortens until the grit can migrate away from the pull direction again. This causes the chain to shorten briefly, until the grit finishes moving.
The last time this happened to me, I was on the interstate south of Colorado Springs (in 1986). I had left Denver that AM, having accidentally reversed the chain while cleaning it: it took about 90 miles for the grit to move. What happened to the bike was: I was tooling along about 70 MPH, and suddenly, over about 1/2 mile, the bike started slowing down and the whole frame oddly felt "stiff". When I stopped to inspect this strange thing, I noticed that when I put my feet down, the bike was TALLER than it used to be, and when I sat on the seat, it acted like the shocks were locked. I tested the slack in the chain (which was 3/4" that AM) and it was like a banjo string(!). I loosened it to 3/4" slack, puzzling, and set off again. At the next gas refill (100 miles or so), there was 3" of slack in the chain! I rode on to Midland-Odessa in Texas that day and the rest of the week around there: on the way back home, I could feel the chian becoming very uneven. At slow speeds it would jerk and tug, and jitter vertically when ridden slowly. When I got home I again removed and cleaned it, and discovered that it had worn very unevenly in that one trip. I talked with a local chain engineer (we had one here in those days) and his first comment was, "Did you reverse the chain's direction?". Yep...