I'm feeling the scorn from afar after admitting to a "rag on a wrench" repair in my last post. Don't deny it! You're scorning me! You think I can't sense that?
Here's the story: I crashed and broke my leg a few years ago. Serious wishbone-style split up most of the length of my right femur. Surgically fixed with a titanium rod, long recovery, the works. Ouch, right? The bike fared much better, with only some mangled handlebar tape, a paint scrape, and a bent derailleur hanger to show for it.
But here's the problem: I'm more than a little OCD. The thought of that bike sitting in the garage with a bent derailleur hanger while I laid around in bed got on my nerves. Maybe (armchair psychology) I needed to fix it since I couldn't fix myself. Or maybe I'm just a freak. Either way, once I was up on crutches, that stinking derailleur hanger became my mental White Whale.
So one night, with my better half (and dedicated caregiver) out of the house for a rare night of not-dealing-with-a-whiny-200-pound-baby fun, I propped myself up and made my way gingerly to the garage. I have no idea how I got the bike off the hooks and up on the workstand, though I'm sure it was ugly. Took off the rear derailleur, wrapped a rag around the hanger, snugged the adjustable wrench over that, and gave a bit of gentle cold-setting -- that's mechanic talk for "I bent it." With no real gauge, I just eyeballed off the dropout and cogs and trusted the floating pulley in my derailleur to make up for the lack of laser-like precision.
At some point in the process, I remember then-neighbor Steve F. sticking his head out his back door, taking one look, and saying, "You're sick!" He was right, but the bike has shifted great ever since, and I slept very well that night. Of course, I was on Vicodin at the time...
Required disclaimer: We're talking about a STEEL bike with a STEEL derailleur hanger here. Steel is a remarkably forgiving material in this situation (though I still wouldn't bend it back and forth a lot). If you have an aluminum hanger, you should hope that it's one of those replaceable bolt-on jobs (though -- whispering -- I've "cold-set" those in my day too). If you have a titanium or carbon hanger, shoot, I don't know what to tell you, other than "if you can afford those, you can afford the right tool for the job and/or a trained professional to use it."