Sheldon Brown's Bicycle Technical Info

Sitting up on the seat

As a kid, I was awestruck by a guy biking nonchalantly past me with no hands on the handlebars. It wasn’t just the no hands though, he was chewing bubblegum while doing it. Two cool things at the same time, with no visible concerns to either safety or time. Obviously, I also wanted to be that badass when growing up. I mean, the kid I saw was probably 10 years old, but still.

Time passed, and now I am old. Thirty-something at the very least. I am unfortunately occupied with both safety and time. But I have knowledge now, and I know a lot more about bikes than that stupid 10-year old kid ever did. I know how to replace a chain, fix a punctured tube, change a bottom bracket, tighten the brakes and how to brake the fastest. I am self-reliant with my transport, like proper cool grown-ups should be. All of that, I owe to the amazing bicycle blog of Sheldon Brown.

The guy and the bike(s)

Sheldon is an interesting character. He is probably the only bicycle mechanic with a dedicated wikipedia article. A slightly plump, seemingly always-smiling guy with a (sometimes dyed red) neckbeard, who owns no less than 30+ bikes. Many of them quite exotic. His blog entries are surprisingly detailed, always starting with a new and corny made-up nickname, like Sheldon “Wrench” Brown or his buddy John “no potato chips, please” Allen. You can find almost everything bike related there, from tandems to fixed-gear and everything inbetween^[1]. There’s stuff so simple you never thought it was a thing, like proper starting technique, or more esoteric stuff, like centering the chainring on a fixed gear bike. You can get lost in tables of outdated bottom bracket standards, or read a guide on how to adjust your specific brake type. He had hilarous april fools jokes. Everything available in a handy HTML-format, just like it should be.

Someone on Slatestarcodex once described the feeling of first discovering the sequences:

“When I first discovered [Lesswrong] a year ago and read the sequences, my reaction was: ‘This is the most amazing thing I have ever read, this has changed my life, Eliezer Yudkowsky must be the smartest man on the planet.’ ...””

I think this sounds familiar to a lot of people who happened to stumble upon Lesswrong or Scotts blog. There was a special feeling of discovering a vast library of knowledge that you didn’t know you wanted. Things you had thought about in some vague sense, were now written down clearly. You might not believe me, but I had the same feeling when discovering Sheldons blog. Where had this been all my life. I was immersed. I had always been impressed by knowledgeable people, and even more so by those who managed to write it all down. People talked about the good parts of the internet, and the good old days before search was broken and AI slop had infiltrated every pore, and I had just discovered one of the old relics. This was awesome, I loved bikes, and of course I wanted to be able to repair them! Now I just needed to read it all.

Self-sufficiency and grokking a bike

Grokking a bicycle is actually kind of hard. There’s an old meme about this, where people are asked on the spot to draw a bike. If you haven’t heard about this before, you should give it a try. It doesnt have to be detailed, just a a stick-figure-like doodle. This seems like it should be easy, right? But the results are not impressive. Even the surface-level details of the everyday bike evades our memory, and that’s just the beginning.

Deeper down, there's a lot of technical details! First off, what even keeps the bike upright? I guess you have heard about pre-tensioned concrete, but did you ever stop to think that a bicycle wheel works by the same principle? Many have dabbled with 3d-printers, and might have heard the term bowden-tube. Obviously when you pull a bicycle brake, the wire transfers the pulling force to the brake caliper. Less obvious is that the cable housing must push too. This is also a bowden tube setup! Or did you know that for pedals, the threads should be normal-threaded on the right side, but left-threaded on the left side? And for (proper) bottom brackets it's the other way around? Me neither, before I read Sheldon.

1. buy bike, 2. Put 2500+ miles on your 10$ chain, 3.replace, 4. Repeat

Thoreau's analysis on traveling where he concludes that traveling by foot is the fastest, is well known. The argument goes like this:
“Thoreau asserts that the fastest traveler is the one on foot. A seeming paradox. But when he goes on to explain, the mystery becomes clearer. In Thoreau’s day, to travel 30 miles by train cost the equivalent of a day’s labor. Thoreau could walk that distance in one day and arrive by evening. The person traveling by rail would first have to spend a day laboring to earn the fare, and then take the train the next day. Thus, the walking man arrived first and had a day full of the pleasures of the countryside.”

The economics of travel have changed since Thoreau’s time, with both the car and the modern bicycle being invented later. However Ivan Ilvich redoes the calculation:

“ The model American male devotes more than 1600 hours a year to his car. He sits in it while it goes and while it stands idling. He parks it and searches for it. He earns the money to put down on it and to meet the monthly installments. He works to pay for gasoline, tolls, insurance, taxes, and tickets. He spends four of his sixteen waking hours on the road or gathering his resources for it. And this figure does not take into account the time consumed by other activities dictated by transport: time spent in hospitals, traffic courts, and garages; time spent watching automobile commercials or attending consumer education meetings to improve the quality of the next buy. The model American puts in 1600 hours to get 7500 miles: less than five miles per hour.”

And he goes on:

“Man, unaided by any tool, gets around quite efficiently. He carries one gram of his weight over a kilometer in ten minutes by expending 0.75 calories. Man on his feet is thermodynamically more efficient than any motorized vehicle and most animals.
[...]
[However] Man on a bicycle can go three or four times faster than the pedestrian, but uses five times less energy in the process. He carries one gram of his weight over a kilometer of flat road at an expense of only 0.15 calories. “

I’m not convinced by the exact numbers here, and I am sure it is possible to do some more or less creative number gymnastics either way you’d like to stretch the result. Both Thoreau and Ilvich seem ideological, and at times extreme for most tastes. But the point still holds, the bicycle is insanely cheap and efficient! Coming back to Thoreau's way of thinking, you can today buy a decent bike for a single day worth of salary, and you can trod on it for years.

Kick down and coast

So the bike is cheap, there’s a huge resource of knowledge available to everyone, and plenty of technical details to grok for the curious mind. All available through Sheldons blog^[2]. Like the man himself says: “I have always loved riding bicycles, especially for the feeling of freedom and self-sufficiency that they give.“. AI doom might be impending, and in some sense things feel less real every day. I don’t want to go on about fresh air, but certainly fresh air feels real. If you yourself are feeling downtrodden, and haven’t been on a bike for a while, why not go tread a bike today? Sheldon shows you how to get started properly__, and if you have any mechanical problems he surely has a description of how you can fix it yourself. You could even go buy some bubblegum and try to do it no handed.