golden gate bridge

May 2nd, 2012

Dear friends and relations,

It’s a dark and stormy night, and I’m sitting in the bike shop watching the headlights of the passing cars glitter off the wet asphalt outside. Ordinarily I don’t stay this late, but the manager has been sick all week, and so since two-thirty I’ve been here by myself, waiting for someone to “come in with a bike. But no one has, since the rain has kept them in their cars. And it has drawn inside, by a sort of osmosis, the various homeless people who inhabit Shattuck Avenue. They visit often enough as it is, but today I have no excuse to shoo them away with, and so I have been sitting at the desk listening to their stories, the dystopian and disjointed narratives of which make Don DeLillo seem lucid. Such is life at the Berkeley Bike Station.

Having lived in the former headquarters of the Tempe bike co-op for two years, I feel guilty that I am now repairing bikes for pay. One of the recurring character types in classical philosophy is the “teacher of rhetoric,” who wanders around the agora and exchanges false wisdom for gold. (Socrates criticizes them and charges for his knowledge exactly what it is worth; Augustine, meanwhile, waits until his 401(k) is topped off before writing his tell-all memoir.) So that’s sort of how I feel. Except I’m not getting any gold. The bike shop isn’t a non-profit, but it’s certainly a not-profit. It would actually be kind of funny were it not so emblematic of the state of California’s finances. It’s not a normal bike shop I work at, you see—it’s a bike parking garage. People bring their bikes in, and we park them. For free. (We also repair them and sell various accessories.) It’s the second-largest bike parking center in the country, behind the one in Millennium Park in Chicago, and is funded by the city of Berkeley and BART. (Incidentally, BART, like most public transportation systems, runs a deficit and is constantly threatening to cut services.) The idea is that it functions as a sort of valet park-and-ride for bicyclists, though not just BART riders can park. Anyone can—and this being Berkeley, does. We make a little money from repairs and sales, but not much, and using advanced techniques of applied mathematics and linear algebra—namely, division—you can calculate that BART and Berkeley pay roughly $3 for each bike we park. It’s not even an equitably-distributed subsidy: probably half of the bikes we park are for commuters who come in daily or near daily. There are maybe 50 regulars who park three or more times a week. I’ll leave the rest of the public choice analysis to the reader.

But the nice thing about having so many regular parkers is that the shop has a real community feeling. We get to see our customers twice a day and be a part of their lives, as opposed to seeing them once every six months in a normal bike shop. This is the least of the luxuries I enjoy: I get paid to fix bikes, I can buy bike stuff at wholesale cost, and—most crucially—have an unlimited supply of free tea. The last of those is not a Bike Station fringe benefit per se, but is rather the donation of a sympathetic barista at Peet’s whose brakes I fixed once. It was an agonizing job. The brakes themselves were old and crappy and so getting the new pads installed took almost forty minutes. You want to align them precisely at the top of the rim, but not so high up that they risk rubbing a hole into the tire, and you want the surface of the pads precisely parallel to the rim (keep in mind that this requires aligning not one but two dimensions), and you want both of the pads to hit the rim at exactly the same time, and for that to be a time at which the brake levers are depressed neither too little (because then they’ll still be far out and the rider won’t be able to squeeze them with as much force) or too much (because then they’ll be too far in and they’ll be limited in how much force they can apply). All of this sounds straightforward, and is, and perhaps if I were an amoeba hovering in a tiny helicopter with a remote control to adjust the system along every possible dimension, perhaps then it would be easy. But brakes are pretty small. The tolerances I want to adjust them to are far below what can be easily achieved by someone with the fine-motor control of a prescription-writer. It’s half a millimeter too high! Dammit! Now I need to start over. You can’t just nudge it up a tiny bit—you need to unbolt the whole thing, re-set it, and hope that this time it’s in position. And simultaneously you have to deal with the difficulty that re-installing it and re-tightening the bolt will rotate the pad ever so slightly. (Dammit! Now it’s an arc-second off-angle...)

The result of spending so much time pursuing of the perfect brake adjustment is that the neuroses in my life that have previously been restricted to punctuation have begun to dangerously metastasize. The same physical pain I feel when I see a comma splice I now feel when I see a bent derailleur hanger. And I see them all the time—not just in the shop, when I’m trying to fix them, but out in the world. I’ve spent so much time now among so many different kinds of bikes that now whenever I walk past a bike on the street, I glance at it, reflexively, and can in just a second or two absorb a huge amount of information about it—it’s a triple, rear brakes need work, bar-end shifters, nice head-tube lugs, etc. For the most part none of that is stuff that I couldn’t have identified before, but it would have taken longer and required closer, more active observation. Now it’s become totally intuitive and automatic. The bikes passing on the street have gone from an anonymous march of wheeled contraptions to a pride parade of unique individuals. The best analogy seems to be to moving to an ethnically-different country: at first everyone looks the same (“they all have black hair! how do they tell each other apart?”), but over time they become differentiated (“look at that group over there—are they Korean?”). The people have not changed, just your perceptions of them, and your perceptions have changed because of your experience. Intuition is not fully natural—it can be developed. It is partly, or maybe even largely, a product of experience.

And then there is the question of language. The bike mechanic says, “It looks like your bottom bracket is a little loose, so we’re going to tighten the cones and see if that doesn’t do anything. If not, we’ll take it apart, clean out the race, and repack it.” To someone who has just dropped off their bike for a tune-up, this is meaningless. It sounds the same as, “We’re seeing some telocytosis on your posterior recticulum, so we’re going to try giving you 10mg of Celerex, but if that fails we may need to do a logoscopy.” In both cases the healer thinks he is being helpful. He’s explaining what’s wrong! He’s describing the course of treatment! But in both cases he has completely failed to communicate. He doesn’t realize that his specialized knowledge of the system encompasses not just what in the system can go wrong and how it can go wrong, but what the system IS. (He knows not just the connections between the parts, but the parts themselves.) The people who bring in their beat-up $400 commuter bikes to get repaired—how do you explain to them what’s wrong? It’s not a question of vocabulary. It’s not as if they call their bike parts by different names. They don’t know what the parts are in the first place. They don’t know how all of the components of a bike fit together to let them ride to work. All they have is a vague idea that there are pedals connected to a chain connected to a wheel, and there are handlebars connected to another wheel.

In the coarse analysis this is exactly how a bike works. They see their bike through a glass, darkly. But repairs are overwhelmingly in the details. The reason their bike is performing poorly isn’t because the chain is broken or a wheel is missing. Their bike is performing poorly because, see, the pedals rotate, which means they have to have something that lets them rotate (the “bottom bracket”). It consists of some spherical steel balls coated in grease—the rotating pedals are connected by a central axle, and so between the rotating axle and the non-rotating bike are these greasy balls that roll and spin and remove enough friction for you to pedal. But, you see, you want to keep these greasy balls rolling and spinning in place, sort of; you want them to be arranged in a ring around the axle—not just wobbling around randomly and falling out. So you have these two things that hold each set of balls (or bearings, I should say) in place. They’re kind of rounded, concavely, so that the bearings fit snugly against them. They look like quarter-pipes, if you’ve ever skateboarded or snowboarded. One of them is attached to the rotating axle, and the other is attached to the non-rotating bike, and they press together and perfectly hug the bearings. They give the bearings the freedom to rotate and revolve, within the constraint that they have to do it in a precise and narrow ring around the axle.

So, anyway, your problem is that these two bearing-hugging-pieces—the one attached to the axle is called the “cone”; the one attached to the bike is called the “cup”—the cup and cone aren’t close enough together, and so the bearings are wobbling around. That’s why your pedaling feels like shit. So we’ll try and tighten them up. Think of it this way: right now, the cup and the cone are hugging the bearings in one of those awkwardly-far-away hugs. That’s not good. If we tighten them too much, the awkward hug will turn into the suffocating death crush of a boa constrictor. That’s not good, either. It would go from too loose to too tight, and you wouldn’t be able to pedal at all. We’ll try to get it to the perfect tightness. There’s a chance, though, that even if we do that, the pedaling still won’t feel great—it might be that the cup and cone are a little bit dented or deformed, in which case we’d probably have to replace the entire bottom bracket. (We can’t order replacements, since there’s not a lot of standardization in how those two parts are made. Every hug is unique.)

How do you tell someone all of this? I mean, I guess one way is to say what I just wrote. In the shop you have the advantage—the substantial advantage—of being face to face with the bike, and being able to point and demonstrate. You don’t have to commit the vulgarity of fitting words to the object; you have the object right in front of you, and can describe it in its own language. But what if the customer doesn’t care? What if they’re not listening? What if they don’t want to hear the details, and just want you to fix their bike? What if they don’t want you to fix their bike, but you know that it’ll be unsafe if you don’t, or that they’ll have to spend even more money down the road if you don’t? What if they already know quite a bit about bikes, and you’ve just blabbed on like a pretentious blowhard for five minutes, wasting your time and theirs? Being an interpreter of maladies is in many ways more difficult than being a fixer of them.

There is a fascinating hypothesis about the origin of life, which I heard a talk about some summers ago, that goes something like this: in the beginning was the Krebs cycle, and the Krebs cycle was with life, and the Krebs cycle WAS life [0]. All of chemistry, in a sense, is an effort to minimize free energy and maximize entropy, and sometimes there are better and worse ways to do this. In thunderstorms, for instance, negative charges build up in the clouds, creating a huge electrical imbalance, and while you could wait for the charged ions to drift down to earth, that takes a while. It’s much faster—much more efficient—for a bolt of lightning to arc between cloud and ground and instantly balance the charge distribution. So the hypothesis is that our metabolism developed as a response to the chemical imbalances of the primordial earth—that life, fundamentally, is a way to reach equilibrium faster. And then on the second day cell walls and DNA emerged.

But, anyway, the connection to bikes is that the evidence for this hypothesis, as presented in the talk, was graph-theoretical: the reactions that control cellular metabolism are virtually the same across all living organisms, and have been fairly well mapped. If you consider metabolism as a complex, interdependent network of 500 or so molecules and tens of thousands of reactions between them, all proceeding according to various differential equations, most of the molecules are, individually, extraneous. You can remove a single element, and the system is robust enough that it adapts and still moves electrons to the right places. But if you analyze the network a bit further, there is a core of a dozen or so molecules—the most highly connected nodes—which removal would completely destroy the system. Those molecules are exactly the thing we had to memorize in seventh grade: the Krebs cycle. So the hypothesis is that the Krebs cycle came about as a natural response to the chemical environment of the early earth, and then everything else in life is simply a detail providing secretarial support to the Krebs cycle.

Well, enough! It is abstract-board-game-night (too many hyphens?) at a friend’s house in Oakland, and there is a set of repurposed poker chips with my name on them.


[0] Harold Morowitz and Eric Smith, “Energy Flow and the Organization of Life”, Complexity 13.1 (2007)