Mea Culpa – Bike Snob NYC

So this past Friday I mentioned my Outside story about the upcoming Silver low-normal derailleur:

Subsequently, in preparing a follow-up post I was looking at a photo I took of said derailleur and noted that the chain run between the pulleys looked kinda funky:

You can also see it here, in one of the photos from the Outside story:

I mostly shrugged it off, figuring it was a stuck link or something. (I’m pretty bad about chain maintenance, and it’s not unusual for me to come across a sticky link now and again.) But then yesterday I saw Path Less Pedaled covered the new derailleur and referenced my photo…

…and in the comments people were all over it:

So I went to check out to the bike and sure enough they were right. You know that little tab between the pulleys?

When I install a derailleur I accidentally route the chain over it instead of under it about 50% of the time. It’s the bike maintenance equivalent of getting yourself caught in your zipper:

Sure enough, that’s exactly what happened here.

The thing is, I always notice it as soon as I spin the pedals around and start adjusting the shifting, because it makes a horrible grinding sound as the chain passes over that tab:

Like, in my experience, you can’t do it by accident and not notice, since the error reveals itself as soon as you turn the pedals.

In this case however not only was there no horrible grinding sound, but I’ve been riding around with the chain like that ever since and I haven’t even noticed. Like, I rode 20 miles on the thing just the other day and nothing seemed amiss:

“How could this be?,” I thought. Spinning the pedals backwards by hand, the chain indeed passed right over the tab. Sure, now that I was aware of it I could detect a little friction, but it was minimal and barely audible. So perhaps between the geometry of the derailleur, the thick coating of sludge on my chain, and the shape and positioning of the tab, the chain was able to pass over it without making a racket.

As for exactly how long I’ve been riding around this way, this latest unit has only been on there since June, though I’d been using an earlier prototype on the Platypus since about April, but judging from the cleanliness of the tab I’d managed to install that one correctly:

Anyway, it’s all rather embarrassing. For one thing, Rivendell grant me the privilege of being the first person to write about their new derailleur, and I return the favor by debuting it with photos in which it’s not even installed correctly. For another, while I may make fun of people who think they can detect the tiny differences between frame materials, apparently I can’t even detect an egregious chain-routing mistake. How is anyone supposed to take anything I write seriously? I mean I don’t expect you to usually, but when it’s a story for a magazine (or whatever Outside is now) it really does expose me for the idiot that I am.

Anyway, the derailleur is now fixed:

But the damage to my credibility is irreparable.