Bicycle Mechanics - plastic bag caused bent RD and hanger!

I'm no grizzled veteran, but I was surprised at what happened to my bike today. I was riding home from work on my '99 Bianchi Volpe (a "cross-tourer", B. calls it), when a plastic bag got blown onto my chain and pulled into rear cogs and rear derailleur. Before I knew it, the RD was bent, and so was the hanger!

Has anyone else ever bent an RD or hanger this way (as opposed to something more obvious, like crashing)? I've never heard of this.

LBS (San Francisco, USA) says $60 to replace dropout/hanger, plus $38 for a Sora RD. At least I didn't go down (it was close, though).

My father once snapped an LX derailleur in half on a bad shift. Very strange, but that's the closest I've seen.

More to the point, your LBS is taking you for a ride. For $39 you can get an Ultegra triple RD ($35 for a double) at Performance http://www.performancebike.com/shop/Profile.html?SKU=1891

Copmpared with Ultegra, Sora is junk. I'd go for the upgrade.

Isn't the Volpe a steel frame? That hanger would reeeeeeeeeally have to be bent to warrant replacement. Hangers on steel frames can usually be bent back into place. The mechanic at my LBS routinely straightens hangers at no charge. Did you buy the bike from this shop?

The price on the derailleur seems steep but I will assume that it includes installation. Call another shop and get some more prices.

Good luck!

I have a friend who lost a handful of teeth when he rode over a plastic bag late one nite! then the broken teeth got infected and things really got bad. That was a few monthes ago...... yesterday he had surgery after being hit by a car last week. He doesn't remember anything at all. they've got a detective on the case. I think he has the worst bicycle luck ever!

First off, I was wrong about the RD: the new one is Tiagra, rather than Sora. (Bike came with RSX, and the other product line names all sound the same to me, frankly. Except Ultegra, of course.) I haven't called around to other LBSes to check on pricing, but it certainly doesn't make sense to compare an LBS price to an online store price, right? Quoted price is part only (I do get 10% off for being a member of SF Bicycle Coalition, a great group). Installation, with new cable, was $15. This is San Francisco, a very expensive city to live in, don't forget -- everything costs more here than in Philly or the midwest (can't say about Japan).

I didn't buy the bike from this shop (different neighborhood, and I like folks and selection of bikes and gear at new place better than where I bought bike).

I was also wrong about replacing versus straightening the dropout/hanger (I was a bit stressed, I guess). Yes, the frame is steel. The hanger was quite bent (more than 30 degrees off), and the hole was quite stretched out-of-round. The shop said US$60 to straighten the hanger and to fill and re-tap the hole, or $150 to replace both dropouts (assuming both needed to be replaced to ensure matched L/R set). Apparently they were able to do the cheaper fix, which entailed some torch work.

I have the bike back now, and it seems fine. I'm still amazed that this sort of thing doesn't happen more often, considering how many plastic bags are flying around in urban streets. At least I didn't go down, or break my teeth -- sheesh, bad luck is right!