Scope Creep, 2024-04-19.

Down to the wire on this one, racing to get all manner of tasks done before I leave for a vacation next week. I will be in San Antonio, Texas, with my family; I hope to take a series of long bike rides, and while I will attempt to continue my writing practice I'm planning on sending exactly zero issues of this newsletter. Which is a big step: SOW (formerly The Prepared) has always published every week, regardless of whether I was on parental leave or my honeymoon or just enjoying a vacation. I'm proud of that fact; I also think that it needs to change; I'm looking forward to seeing how it goes.

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SCOPE CREEP.

• Let's do some jobs:
  • Artisan Insight is hiring a senior electrical engineer in San Francisco.
  • GaeaStar is hiring an entry-level manufacturing engineer in San Francisco.
  • Redwood Materials is hiring a director of electrical & firmware engineering in San Francisco.
  • Specialized is hiring a senior design engineer for mountain bikes in Auburn, CA.
  • Formlabs is hiring a head of global sourcing in Somerville, MA.
• hitchBOT was a hitchhiking robot, made of pool noodles, rubber gloves, and a cake tray. It could listen (via a Google Voice recognizer) and speak (via Cleverscript), both running on a tablet computer. hitchBOT was designed to "ironically assume the risks and fears associated with hitchhiking," and in 2014 and 2015 the child-sized humanoid successfully hitchhiked across not only Canada but also Germany and the Netherlands; it was then destroyed, in what was apparently a prank, in Philadelphia.
• I've been spending some time looking at high end road bike factories, attempting to find one which will let me write at length about their assembly processes. (I visited a series of bike factories in 2015, and published fairly extensive notes, but the purpose of the trip was not primarily to write about it.) There are a bunch of high end, carbon fiber road bike factories in Xiamen, China; one of them, LightCarbon, has a fairly detailed "technology" section of their website which includes technical drawings and 3D models of frame molds, images of their mold storage racks and molding process, videos and specs of their frame, fork, and handlebar tests, and a sped-up, five-minute tour of their headquarters.
  
  It used to be that bikes were made of round tubing – steel, aluminum, or carbon fiber composite tubes, whose outer diameters were constant and whose wall thicknesses varied along their length. With the advent of hydroforming (which I don't have the space to write about here, but you can watch a very lo-fi video of) it became possible to create non-round tubing at scale. But hydroforming tends to be used on heavier bikes – mountain bikes – and my sense is that the design consideration has to do more with stress concentration than with aerodynamics. Carbon fiber composites, which dominate the high end for both road and mountain bikes, are different, and a lot of work today is put into improving aerodynamics. One common strategy, used in particular on seat tubes, is the Kamm tail shape, whose section looks like a capital D moving through air with the round side forward. Kamm tails are common in automobiles, and as this article describes, they tend to provide good aerodynamics while retaining headroom in the rear seats and decent rear window visibility.
• I read the first bit of Computing Taste for the SOW Members' Reading Group the other day, and was struck by an aside on the nature of secrecy within social interactions:

What my encounter in the Willow lobby made clear was that anthropologists of secrecy commonly argue: secrecy is not a wall holding information back but a "relationship between insiders and outsiders"—a pervasive social accomplishment, embedded, as the sociologist Georg Simmel put it, in "the finest meshes of social forms." Whenever I spoke with someone who worked for a company, we jointly negotiated this boundary, determining what would count as "inside" or "outside" and what rules would govern our exchange.