This just in... mechanic defeated by his own hubris.
I'd pulled off a pretty slick repair on our tandem so it would be ready for the farmers' market yesterday. I was feeling pretty good about myself. There was even some mention of my candidacy for the coveted Greatest Living Bicycle Mechanic in Central Iowa title.
Not so fast, slick.
I've been chasing a creak around my main ride, eliminating possible causes through a slow diagnostic process. Today, I had enough time to pull the cranks and bottom bracket. The plan was to grease the shoulders of the bottom bracket cartridge where they sit in the cups and wrap the cup threads with Teflon plumber's tape. It's an old trick from my days as a Cannondale mechanic, since a dry BB install would invariable make a small creak that would resonate through those big aluminum tubes until it sounded like a door opening in a horror movie.
That was the plan, anyway. And it worked for a while. I got everything out, cleaned it all up, greased up the cartridge, wrapped up the cups, and got the right side cup back in the frame, straight out of Sutherlands.
So, I started the left cup. And it felt a little snug. Before you ask, yes, I did know which cup had left-handed threads. Straight out of Sutherlands, remember?
"No biggie," I figured. "The Teflon tape makes it tight." So I kept cranking.
And it got even more snug. "Man, I must have put too much tape on that thing," I figured. So I grabbed a bigger adjustable wrench, clamped that bad boy on my BB tool and kept cranking.
It got even more snug. I could barely budge the thing, and it was barely a third of the way in. Only then did Mr. Fixit think, "Huh, that doesn't seem right." So I started backing it out again.
Cross-threaded. The aluminum cup was absolutely shredded where I'd ham-fisted it sideways into the steel bottom bracket shell. This is a family blog, so let's take the "edited for TV version of Snakes on a Plane" approach and pretend that I said, "I'm such a monkey-fighting idiot, cross-threading this Monday-Friday bottom bracket."
Proof that someone or something up there is looking out for morons and klutzes, at least it was an aluminum cup that sacrificed its life for the steel bottom bracket shell. If I'd needed the BB threads chased late on the Sunday of Memorial Day weekend, I would have been stuck. And I made a decent save by pulling a cup out of my fixie that just happened to fit despite being an entirely different brand of cartridge bottom bracket. So, the fixie's down until I replace the cup, but at least my daily driver is going again.