3014 points by todsacerdoti on March 28, 2023 | hide | past | favorite | 399 comments

 I wrote my master thesis on optimizing bicycle wheels / spokes. I actually see I'm cited in the phd he cites, quite a fun surprise!This is a great article. It showcases lots of the "simple, but surprisingly advanced" things surrounding bicycles. Which was what got me hooked in the first place. The visualization of how you have to turn right to go left is excellent. I've mentioned that fact multiple times here on HN, it's not commonly known, you just "do it" when you bike! And it explains why you sometimes can feel the curb "sucking" you towards it when you try to avoid it: you unconsciously avoid turning the wheel towards it, but that actually makes it so that you're unable to actually steer away from it!
 Veritasium did a great video on the opposite direction turning. They even show a bike that prevents you from turning the wheel one way to show that its essential.
 When I took control theory at university, in the last lecture, the lecturer took out a bike with rear wheel steering and challenged us to ride it in the hallway outside the lecture hall in the break. No one could get it to roll more than a couple of meters. The second half of the lecture was spent proving that a rear wheel steered bike is in fact (almost) impossible to control.
 And in opposite world: Rockets with steering thrusters near their top are highly unstable.
 At some point (some) people though rockets with the thrusters near the top would be more stable. See e.g. this rocket by Robert H. Goddard: https://en.wikipedia.org/wiki/Robert_H._Goddard#/media/File:...But it turns out that it doesn't matter whether you place the thrusters high or low, stability-wise. What matters is that the center of mass is in front of the center of the center of pressure.
 hoseja on March 29, 2023 Aren't they just as stable as regular rockets, but it's very inconvenient to put the thrusters on top? It's called pendulum rocket fallacy and from what I can tell that's the case.
 kqr on March 29, 2023 Huh, wouldn't this be similar to riding a regular bike backwards, which a lot of people (although not myself) are able to do?
 Yes, it was pretty much a reverse bike with the saddle on the frame and a handle bar just behind where the seat post should be, connected to the steering axle. The details is a little bit fuzzy since it was a couple of years ago but iirc it is actually possible bike backwards at slow speeds but require a lot more active balancing from the rider, and at some point it becomes impossible as the speed increases. Also it concerned the case where the bike is riding straight ahead, it is possible that it is easier to control if riding in a curve.
 Groxx on March 29, 2023 In the extreme, it's also equivalent to a unicycle - just lean back to put all your weight on the steering back tire. Unicycles can be controlled.Both are undeniably less easy than a normal bicycle though.
 dizhn on March 29, 2023 > opposite direction turningThe term used in motorcycling is countersteering. A lot of people think they are using their body to change direction but that would not be sufficient. Also it helps to be deliberate about the handlebar pushing motion for safety and performance.
 _jsnk on March 28, 2023 I also recommend the SmarterEveryDay video[0] where they rig a bike to turn the opposite way than it is steered.
 A fair bit of the stability of a bicycle (especially at low speeds) is due to the fact that you have a human holding onto a bar that behaves exactly like a thing that a human would grab onto to steady themselves. If you grab this bar and rotate it clockwise, then you yourself will rotate anticlockwise - and that is true whether the bar is the handlebars on a bike or a random bar fixed on a wall. Holding ourselves steady by grabbing onto something is something that humans have a remarkably effective and quick feedback loop for, which is why bicycle riding comes naturally once you get over the fear of falling off and just do what feels right.Rigging the handlebars to turn the wheel the other way cancels out that automatic feedback loop.
 > ..you sometimes can feel the curb "sucking" you towards it when you try to avoid itI was shopping for a kids carrying bikes, called bakfiets[1] (I think) in the Netherlands. The salesperson offered me a trial ride, his advice is something I still remember. Don't bother about the front wheels (they are far out in front), just look where you want to go and your hands will take care of steering and balancing.Edit: fixed thanks to the correction by “isoprophlex”!
 Drop the space between "bak" and "fiets". Just "bakfiets", otherwise you don't mean the noun for cargo bike, but the imperative "bake a bike" ;)
 Fixed, thank you :-)
 sasawpg on March 29, 2023 Target fixation - you'll go where you look, for better or worse. Inexperienced riders will often stare right at the obstacle they're trying to avoid and ride right into it.
 KeplerBoy on March 30, 2023 You went bakfiets shopping as a novice rider?Sounds brave. Did it work out?
 I'm sure the poster meant it was their first time riding a bakfiets, not that they never rode a bike before. The length of the bakfiets makes it a bit of a challenge.
 The counterintuitive turn is more pronounced in motorcycles. You are literally pushing against the turn as you lean into the turn, and to lean in you have to turn out. Even more pronounced in sport motorcycles. Maintaining the centre of gravity during a lean at those speeds is a lot of fun to master. It’s one of those heart racing moments, literally no room for error.
 Indeed, if you want to make fast turns at speed on a motorbike the trick is to first push/pull the bars in the oppositive direction - that gets the bike leaning over and then the bars come back and take the natural position for the turn. It's amazing how quickly even a big, heavy bike (e.g. BMW tourer) willl lean over with the right technique. At very highspeeds it takes quite a bit of muscle too.
 I took the Motorcycle Safety Foundation basic course a very long time ago. One of the instructors brought his Honda Goldwing to the course just to help us get over the fear of falling over by showing that even a massive heavy motorcycle could go through all the tight turns without any problem.I have to say, that course was some of the most fun I've ever had!
 One of the best decisions in my life was to take this course. I started riding a Buell after this and boy what a thrill it was to lean this bike in the Pacific Northwest hilly roads.
 Rapzid on March 29, 2023 Yes. On a motorcycle at high speed you have to actively maintain force on the wheel towards the outside of the turn to keep in the turn. If you stop the bike will straighten up.
 Unicycles have a similar counter-intuitive control method where you need to accelerate the wheel to slow down and vice versa. Turning doesn't work quite the same way though as you can do sharp turns by twisting your hips and thus changing the direction that the wheel is pointing.
 Never thought about, but yeah I guess it makes sense. If you were to suddenly stop you would be jolted forward, so need to get a bit behind the wheel first.(too late to edit my original comment, but here is a link to my thesis discussed at the time: https://news.ycombinator.com/item?id=10410813 )
 Many times I've observed myself as closely as I can taking a turn. I can't observe any steering in the opposite direction. I start by leaning, then turn into it (if I turn the wheel at all, which I don't unless the turn is very sharp). Maybe I really do steer the other way some imperceptible yet vital amount? This summer I plan to weld a bicycle unsteerable and see what happens when I try to steer solely by leaning as it feels like I generally do.
 The welding the bars experiment you are talking about is done in a motorcycle school I once took with Kieth Code (California Superbike School), in order to prove to riders that countersteering is real.I held an American Pro Superbike racing license in my 20s and countersteering is the only way I ever steered. Here is an experiment - go into a flat and wide open space like a parking lot, ride straight, and then turn to the right hard while keeping straight up and down. Hold the pressure to the right and I promise you will turn left or will initiate a turn to the left. The harder you turn the bars right the quicker the bike will fall left and begin arcing left.In chicanes on a circuit track you can flip the bike over from one side to the other extremely quickly doing this. I've done this on everything from mountain bike to superbike, the latter being a more pronounced effect.The only time I don't countersteer is when doing a 180-ish degree turn on a dirtbike, like what is common on an SX course. Also, when doing an extremely slow turn on a sport motorcycle, like what's common in USA motorcycle safety courses. But when moving at speed I always countersteer.Knowing this phenomenon and using it may save your life.
 loeg on March 29, 2023 Countersteering helps initiate that lean more quickly than just organic falling over. It's possible you're exceptionally patient but it's also possible you're just countersteering a little bit to initiative the lean, without noticing it.
 jrockway on March 29, 2023 Interestingly, I read about this a long time ago and intentionally turn the handlebars the wrong way to initiate the lean. (Not because it's necessary, but because it's weird. Riding your bike can be boring at times.) Very smooth.
 It's totally necessary to push the handlebars in the opposite direction to initiate the turn because bikes are not minimal phase systems (at least that's what i remember from control systems).
 ergonaught on March 29, 2023 It is unconscious and you have no idea you're doing it.Watch the Veritasium video linked earlier. It's good stuff.
 I've watched it multiple times and I'm not entirely convinced I don't tend to turn in some different way from the average person. One person managed the turn correctly by accident in the video because they'd happened to lean the right way beforehand.
 mnw21cam on March 29, 2023 It's easy to see countersteering in action if you have a quiet damp road. Try riding in a straight line and then turning to the right. Then dismount, walk back to where you started your turn, and have a look at your tyre tracks.
 komali2 on March 29, 2023 How thick are your tires? Initiating the turn requires just the tiniest bit of countersteer on very thin tires, in my unstudied experience. I did the same experiment as you and found it was so subtle as to be basically unnoticeable.
 Yeah on a motorcycle leaning doesn’t do anything to engage a turn. “Push the direction you want to go” is what’s drilled into you and also just feels natural.
 There's a YouTube video where they do exactly this. It doesn't end well for the rider.
 I read once that when draisiennes first appeared in 1817, it was a surprise to the inventor that you could in fact lift your legs up and balance.I forget completely where I might have read or heard this, but I love it so much I'm going to keep telling it. Can anyone confirm?
 I can at least confirm that my daughter was very much surprised when her balance bike [0], which is essentially a small draisine, stayed upright when she lifted her legs.
 That’s gotta be a cool feeling to see your work cited in other research. Kudos!
 Similar concept that gets a lot of people in trouble on the OneWheel, "lean forward to slow down". When you're going to fast, the you intuitively lean back, which actually accelerates. There's even been a handful of lawsuits around this physics issue.
 But why can't the inability to make a sharp turn be explained by the need to arrest forward momentum? The momentum has to change direction. Turning 90 degrees causes sudden loss in velocity. Turning against the arc of the turn i.e. along the orbit of the turn transfers the forward momentum into angular momentum. Thus, a counterturn is just an efficient way for the bike to follow the arc.Higher the velocity, the larger the arc required.
 Gyroscopic forces are fun. That phenomenon kicks in around 20-25 mph but that’s when I was on a crotch rocket. I’ve experienced it at like 15 mph on a bicycle.
 This is an important concept when riding motorcycles at higher speeds. This was taught in the class I took to get my motorcycle license.
 > I wrote my master thesis on optimizing bicycle wheels / spokes.Any practical outcomes for hobby wheelbuilders with conventional parts (like some sort of novel lacing pattern or something like that)?
 It was mainly a CS thesis on multi-objective optimization algorithms, and wheels were my chosen application. So me not being a mechanical engineer I didn't exactly push that side of the science any forward.But my algorithm did end up "inventing" the 3x pattern perfectly, which I think was cool. Both as a confirmation that it's really a good versatile pattern being pareto optimal in multiple objectives, and the algorithm finding it also verified that my approach did have some merit.Of the "unconventional" ones it found, my favorite I ended up using for the cover: https://i.imgur.com/b1ImCo8.jpg
 Beautiful! Thank you for sharing :-)(Just saw that you quoted the n+1 rule in the preface, hehe.)
 lqet on March 29, 2023 That is a beautifully bound thesis.
 samstave on March 29, 2023 Please send me hard copy of thesis.\$ I have coin if you have warez.
 samstave on March 29, 2023 HI!Thank Odin I found you!-I have a conceptual wheel design idea that I feel that only you can accomplish a successful design...Before I email you some rambling wall of text, would you be open to hearing about some crazy concepts?--TL;DR:The idea is to use Toroidal Propellers as 'spokes' in various light-weight, 3d-printable 'turbines', along with wind-shrouds to force vector air current to dynamos... specifically in various scaled applications for objects which already have a rotational input (shaft, wheel, spinny thing, etc)Open to hearing from the loony bin?Where read thesis?Also, I am Norwegian! (but from Ballard, Seattle)---People tend to think of 'scaled' as in "LARGER" -- but it can also be used to refer to smaller...Think of toroidal pumps in tiny bio tubes (veins, maybe, distributed heart pumping/nutrients pumping to isolated bio-assets (simulate pumping of heart of external bio-fluids to individually separated muscles connected to a biovascular pump system that can mimic the actual heart pattern of a donor to keep tissue happy) perhaps?)Anyway -- its the evolution of Davinci's first documenting the importance of eddies, which we later discovered is how pumps work... (We knew pumps, but we didnt understand how they worked (documentedly) in Archemedies time (we also 'know' he did "discover" this, he documented it...) Anyway... (Sorry for the rant)I want to develop a way to capture the eddies around certain objects.... If we examine Whales (the animal) they have a symbiotic relationship with barnacles... the barnacles attach to the leading edge of their fins. Whales eat off of plankton, small critters...The barnacles create eddies along the wing surface..BLAH BLAH BLAHAnd the eddies feed both.... And I would like to talk to you about how this impacts flight! (passive extendable props that are fed off eddy wash) and pumps, and fluidic dynamics... and a bunch of cool boring shit.
 wiredfool on March 29, 2023 Get a copy of the Bicycle Wheel by Jobst Brandt.(and then try to map that experience onto current spokes/rims, which are somewhat different)
 With motorcycles, you gotta learn “push right to go left” or you’re gonna end up in a bad sitch! But the physics of it are pretty mind boggling.
 Similar to the 'bees can't fly' thing. I never, ever crashed my bike until i learned how not to. And where not to look.
 Never heard of it. Show us this... the wheel
 The “kerb sucks you in” phenomenon is target fixation, you’re getting closer to the kerb because you’re staring at it. It’s a common cause of motorbike accidents, among other things.
 You often see these two concepts (target fixation and counter-steer) discussed in threads on steering.Not denying that target fixation is real and operative in some circumstances ... but counter-steer is even more "basic" in that it is solely a function of two-wheel dynamics, not rider psychology. You really do need to steer slightly right in order to initiate a turn to go left.See the video linked up-thread.Here's a page from a motorcycle POV which has a "truck pulls alongside" anecdote similar to your "riding parallel to curb" example: https://www.insurance.harley-davidson.com/the-open-road/tips...
 No, it's because there's not enough room to counter-turn to shift your balance.
 Well, it's probably also because of target fixation.
 Wow, they really don't like being told "you go where you look".
 Relevant link that I saw on HN earlier this week: someone asks people to sketch bicycles and then renders the sketches.https://www.gianlucagimini.it/portfolio-item/velocipedia/> Little I knew this is actually a test that psychologists use to demonstrate how our brain sometimes tricks us into thinking we know something even though we don’t.> I collected hundreds of drawings, building up a collection that I think is very precious. There is an incredible diversity of new typologies emerging from these crowd-sourced and technically error-driven drawings. A single designer could not invent so many new bike designs in 100 lifetimes and this is why I look at this collection in such awe.
 > how our brain sometimes tricks us into thinking we know something even though we don’tThe way I try to avoid this is to remind myself that knowing the name of something is not knowing about something, only about the existence of that something.There are lots of things I know the names of, but relatively few things I actually know about.The classic example is asking people to describe the process that causes the phases of the moon. Most (myself included the first time) describe an eclipse, which is wrong.
 > He explained it like this which really helped: you can choose all sorts of frames of reference when you think about this stuff, so choose one where the sun and earth are stationary compared to each other, and then only the moon is rotating - less stuff to think about!Even easier: choose one where the sun and moon are stationary, and place the Earth somewhere near the moon. The side of the moon facing the sun will always be fully brightly lit, and the proportion of that which is seen from the Earth is based on where we place the Earth.Of course the Earth doesn't orbit around the moon, but for the purposes of this model it's irrelevant.
 I would explain it like this: take a tennisball and shine a flashlight on it from one side. Make sure you do not see the origin of the light by holding it just right of your shoulder.
 I 100% agree with your comment however in regards to it's relationship to the parent comment I have to disagree somewhat in the usual nitpicky hackernews fashion:Asking someone to draw "a bicycle" is different to asking them to draw a specific bicycle or a functional bicycle. Also what does it mean to "know something"?If you ask someone to draw a house and they draw a square with an overhanging equilateral triangle centred on top, it's not that they don't know what a house is. That's just a symbol representation of their own personal definition of a house.
 The equivalent here would be if you drew that same stick-figure house but put the door adjacent to the roof rather than the floor, or the triangular roof along one side rather than opposite the ground.
 grog454 on March 28, 2023 > remind myself that knowing the name of something is not knowing about somethingYou and Feynman both: https://youtu.be/px_4TxC2mXU
 It's quite likely that that's where I got it and then just forgot.
 This happens to me alot. Motivated by curiosity I will make the effort to acquire a piece of knowledge but since I don't have a functional use for such knowledge parts of it slip out of memory....then some time after I will have a functional need for the knowledge I learnt previously but relearning something that is already somewhat familiar isn't that captivating so it ends up being a struggle the second time.
 What a great example! As a recent astronomy enthusiast, I found myself doubting this comment initially ("well, eclipses ARE related"), and this despite the fact that I have a toy tellurion right by my desk.But hearing a particular phrase in the below video helped correct my model. One sanity check is that you can see non-full moons during the day (although I definitely would have just assumed it was still a matter of angles).Related video: https://www.youtube.com/watch?v=Jip3BbZBpsM
 Side comment: This is the first time I've seen my preferred username used for its actually meaning. And I've been using it for almost 3 decades. Neat. I was going to use tellurian, which means an inhabitant of the earth, then saw that tellurion was sometimes used as an alternate spelling in an old Webster's dictionary I was looking through, and preferred it. And yes, I did search through a dictionary to find a username.
 stouset on March 28, 2023 > The classic example is asking people to describe the process that causes the phases of the moon. Most (myself included the first time) describe an eclipse, which is wrong.To me, a neat consequence of this is that if you know what part of the cycle the moon is in, you know where it will be relative to the sun in the sky (and vice versa).
 The trouble with the very first render is that the author is wrong about why the bike wouldn't work. The head tube isn't braced well enough to allow the front brake to be used, and would twist when cornering to a degree that would unsettle most riders. The missing chainstay would only be an issue for powerful cyclists or people standing up to pedal. But the bicycle shown could definitely be built and ridden. Probably more practical than Saul Griffith's plexiglass bicycle (that was also built and ridden).At one stage Klein had a problem with the chainstays separating at the bottom bracket and a number of people rode those bikes after breaking them... almost exactly the "missing chainstay" problem above.I've built some very weird bicycles and broken both those and conventional bicycles. I have at least some idea of what works... I'd be willing to build as many of those renders as someone was willing to pay for.
 Nothing about the rendering specifies that the frame isn't made of solid steel rods.Aren't you assuming that it's a tube of the same thickness as a typical bike?And furthermore, that someone building it wouldn't be allowed to make obvious accomodations to reinforce the parts of the frame under stress?E.g. [1] shows a bike for sale with similarly lacking bracing of the head tube.
 A missing top tube is much easier to deal with than a missing down tube. Lots of bikes have pushed that a very long way. But the main forces there are twisting the pedals against the handlebars and using the front brake, which the downtube is very involved with.You could build that bike out of steel tubing and it would be rideable, as I said, but insofar as it's broken it's broken at the missing down tube.Slingshot, for example, had no down tube just a wire and that was a bit notorious for being squirrely in the steering.You could definitely build a bike like that that was quite rigid, it would just be heavy or expensive or both. A decent carbon layup, for example, might bring it back to the chain forces going through the seatstays being the main issue. But that's something you'd want to analyse a lot before building it. And I think you'd end up wanting a much bigger head tube lug than shown.
 taneq on March 28, 2023 Sounds like you’ve spent a lot of time experimenting! Got any pics of the weird bicycles?
 https://moz.geek.nz/mozbike/ride/carry/index.htmlI didn't collect photos of the real experiments, those were mostly "grab a scrap bike, hack it about, (try to) ride it, bin it and try again. But if you wander the mozbike site there's a few of those. https://moz.geek.nz/mozbike/see/misc/2001/index.html has the "MBB FWD recumbent" that's just a cheap chair welded to a BMX frame :)
 Great album! Have you done any more interesting bike projects more recently?
 nothing interesting, just repairs and tweaks. I'm building a granny flat instead :)
 Reminds me of how AI image generators draw stuff slightly wrong
 Came here to post this. I would love to see all the same force animations but with these models swapped into them.
 this was one of the greatest installations i've ever seen in an art gallery. You have no idea what you're looking at until you've passed through all the rooms...seeing a real life "fucked up" bike in the last room...is a little mind blowing haha
 The most important fact is that riding a bicycle is 3 to 5 times more energy efficient than walking. Depending on the road, bicycle, terrain and weight of the rider. Riding a bicycle is the most efficient self-powered means of transportation.
 It's no coincidence that other human-powered transport mechanisms (aircraft, boats, etc.) commonly use pedals for the drivetrain. It's a lightweight way to use the body's strongest muscles, especially when high power is critical.See:
 I wouldn't say it's common at all in boats. The two main human-powered boats are canoes and kayaks, and both use the arms, not the legs. There's also rowboats, which again use the arms. Pedal-powered kayaks do exist, but are rare.It would make more sense to use the legs, but it's a much bigger engineering challenge than making a simple paddle and a boat that floats with no holes in the bottom.
 That's certainly true--oars are by far the most common configuration for human powered boats. I was thinking more about human powered boats that set speed records, e.g. the Decavitatorhttps://en.wikipedia.org/wiki/DecavitatorA lot of this might just be because Mark Drela, who was involved in the design of several of the aircraft and boats on this list, is a cyclist.
 rstupek on March 29, 2023 Rowing is not solely an arm mechanism but his actually driven by the legs
 As a rower myself I wanted to type the same correction initially, but then realized that the parent comment is probably referring to a rowboat rather than a racing shell. No sliding seat, no leg drive.
 Rowing in a real rowboat has little to do with the legs: the seat is fixed. It has a lot to do with the back, however."Rowing machines" have very little to do with real rowboats. Real rowboats don't have sliding seats.
 Sliding seats are used for competitive rowing. For example: https://en.wikipedia.org/wiki/Rowing_(sport)#Technique
 When normal people talk about a "rowboat", this is what they're referring to:
 I had a look and the source cited for it being the most efficent self-powered means of transportation is from March 1973; I wonder if there's been any new developments since then.Random things off the top of my head: Some time ago they built a self-propelled helicopter, which also used bike technology (gears etc). I vaguely recall that people did state that rowing is what you should use to get the most energy out of a human body - it is (or can be) a full-body motion, including the large muscles in the back and legs and the smaller ones in the arms, while cycling mainly uses the legs. But the mechanism to translate rowing energy into the propellers was too heavy, or something like that.Actually it might have been a HN thread. Here's one from 10 years ago, and it just so happens that I had made my account by then so this was probably it: https://news.ycombinator.com/item?id=6028326
 I read somewhere (lost to the fickle beasts of memory and time, of course) that rowing and the like is not particularly effective, precisely because it requires big, slow movements against resistance, which the human body is not that efficient at[1]. What we are efficient at is quick, light, repetitive movements – like pedaling with the proper gear selected. This is why Ivan Illich phrased it as the bicycle being "the perfect transducer to match man's metabolic energy to the impedance of locomotion".[1]: This is also why rowing and weightlifting are such a good type of exercise to get stronger, and why bicycling requires that you put in a lot of hours to get stronger from it.
 Psychlist on March 28, 2023 > I vaguely recall that people did state that rowing is what you should use to get the most energy out of a human bodyThe limit for athletes is normally cardiovascular, commonly oxygen - VO2max the the measurement there. For less fit people it can be the cardio side, their heart just isn't up to it so their muscles fail and they lie on the ground twitching. Oxygen-deprived people pant and gasp.So recruiting more muscle groups really doesn't help. What does is increasing oxygen intake, and this is where recumbent bikes come in. The laid back position opens the thorax and increases effective lung capacity. As well as reducing air resistance, except that that's a very subtle thing that mostly depends on the rules governing the sport in question (fairing on bike and kayak, for example, are variously restricted or banned in most relevant sports).You can also reverse that and exercise at high altitude... less oxygen for everyone!
 > So recruiting more muscle groups really doesn't help. What does is increasing oxygen intake, and this is where recumbent bikes come in. The laid back position opens the thorax and increases effective lung capacity. As well as reducing air resistance, except that that's a very subtle thing that mostly depends on the rules governing the sport in question (fairing on bike and kayak, for example, are variously restricted or banned in most relevant sports).Recumbent riders generally have much lower peak power and ftp but higher sustained so VO2 differences wouldn't explain it. The main attribution I've seen is aero and marginally less muscle power used for motions that aren't related to pedalling.
 My limited experience is that it's easier to recruit more muscles on an upright, so your peak power can be higher. In my 30's I would hit double for a 30s trial on an upright vs a recumbent (last time I had a decent power meter was in my 30's). But over 5 minutes the recumbent was better even if both were fixed to stands. So I don't think it's the balance issue.For an hour or more the recumbent wins just for comfort, and unfaired records it wins on air resistance (that's why the UCI banned them, it let povo scum beat gentlemen athletes). But then the UCI doesn't have faired records... it's only the IHPVA et al that make that distinction.Interestingly the PBP etc records (we don't have records, this isn't a race!) are all uprights AFAIK. But that's xenophobia rather than technical skill from what I know. And the Round Australia record is an upright, largely because no-one on a recumbent has been inclined to attempt it. RAAM is held by a bent (https://en.wikipedia.org/wiki/Race_Across_America#Records).
 Recumbents are notoriously difficult to ride as the grades get steeper. Upright cyclists have the advantage using different body positions (i.e. standing), but 'bent cyclists can't do that. On the steepest grades, it can be a challenge to even keep a 'bent's front wheel on the ground.
 hoseja on March 29, 2023 Sure but then you have to ride a recumbent bike like a dork.
 If we take distance passed as a measurement, intuition tells me that bicycle is more efficient, since it doesn't have to lift the whole body, just move it around on wheels which provide very small friction.Perhaps if we had bicycles with comfortable seats we can recline in, we could save up energy needed to balance our body on a bicycle. Something like a pedal boat, but with wheels.
 Recumbent bikes definitely are more efficient due to aerodynamics if nothing else. I suspect being able to push back against the seat helps too, though.
 This is true - the ergonomics as well as the aerodynamics are a step up. I would like to note though a disadvantage in ergonomics when it comes to hills, which nicely illustrates another feature - often unacknowledged - of conventional frames. I live on a hill and commute on a conventional/non-recumbent bike. There used to be a bearded white middle-aged guy living half way up our hill with a recumbent and I noticed the recumbent seemed way /less/ efficient on our hill climb. A secondary design feature for conventional bike geometry is how well it works on a hill when you stand up. There’s something about how you can use your weight, pulling on the handle bars at the same time as rocking the bike frame side to side, to maximise downforce on the pedals, that just works incredibly well for propelling yourself and the bike up a hill. None of that is available on the recumbent designs I’ve seen, and because the hill slows everything down, they get less aerodynamic advantage too. So while they’re great on the flat, I think a key limiting factor for recumbents may be that they’re not so good in hilly places.
 Ran into a fellow touring once with a recumbent and a trailer for his dog! All told, a 250lbs rig, few would be able to celebrate as much getting to the top of santiam pass in oregon (approx 4000 ft climb)!
 acomjean on March 28, 2023 I've seen a few of them in the city. The seem great, but I wonder how well they steer. They're low to the ground and seem less visible (I've seen them with flags). On a bike your center of gravity isn't much higher than walking, and you can put your feet out quickly and essentially be in a standing position .
 They steer well enough for bike trails. Longer (e.g. tandem) ones may have some challenges with tighter turns (need to do a 90° adjustment at a light).Flags are common for recumbent for visibility.The lower center of gravity and the "it's real hard to fall off" can make it useful for people that have difficulty with balance. The back seat of a tandem is suitable for someone with needs for additional assistance ( https://www.terratrike.com/product-category/accessories/assi... ) - my mother would go tandem with one of her friends who was legally blind and needed to use a walker.
 samstave on March 28, 2023 I bike A LOT -- >1,000 a month on a 29" full suspension e-bike (Orbea Rise)But I have been biking daily for morethan a decade, and was a daily bike commuter in the bay area for ~15 years....I see many recumbent bike a day when on the trail. At least >5 a day.My house backs up to the American River trail, I literally leave my house and get directly onto the trail in less than 2 mintues.Recumbents are all over the ART in the Sacramento Area.One thing I have noticed though, and this is just a statistical observation on my part biking that trail regularly for ~2 years...The average Recumbentist is a White Male, Typically with a beard >50 years old, 30% are overweigth, 30% are average build, 30% look semi/more-fit, 10% are female.They look fun though. I'd love a long distance camping -e-bike version of one with a trailer and a detachable, light, curved windscreen that can be put on the top of the trailer when one wants.
 > The average Recumbentist is a White Male, Typically with a beard >50 years old, 30% are overweigth, 30% are average build, 30% look semi/more-fit, 10% are female.Recumbents also used to be far more expensive than standard bicycles (although now there's a lot of expensive standard bicycles) so an older demographic isn't surprising.Recumbents are also lower in height and a lot easier on people's joints so are particularly good for people who have medical issues or mobility impairments. So, again, your demographics aren't surprising.
 Yeah, no slight on recumbents! I want one.Oh, and the other demo is 100% of them are wearing 'Gardening hats' (A hat you tend to see people gardening in...)
 shagie on March 28, 2023 > They look fun though. I'd love a long distance camping -e-bike version of one with a trailer and a detachable, light, curved windscreen that can be put on the top of the trailer when one wants.https://bikeportland.org/2009/11/10/portlands-terracycle-unl...That company appears to be https://t-cycle.com
 grayrest on March 29, 2023 > The average Recumbentist is a White Male, Typically with a beard >50 years old, 30% are overweigth, 30% are average build, 30% look semi/more-fit, 10% are female.I'm white, male, beardless, and 40 and am almost always the youngest when showing up at a recumbent meetup.A lot of the current crop of recumbent riders (in the US at least) got into it in the late 90s and early 2000s. As the boomer cohort aged out of riding two wheeled recumbents there was a significant drop in demand for recumbent bicycles and a corresponding increase in recumbent tricycle demand. The companies making fast/racing recumbents stopped due to lack of demand (basically just Performer and Bacchetta are left) so there aren't a lot of us left in the fast recumbent bicycle crowd and almost everybody is running a 10+ year old bicycle. I have a 2009 Optima Baron, for example. More casual recumbent bicycles like LWBs or crank forwards are still around and seem to be more popular in the midwest than on the coasts. I live in NYC and recumbents are particularly rare here due to the downsides of recumbents in the city, mostly sight lines in traffic. I've seen 6 in the wild in the last 8 years and I usually see 4 or 5 recumbent trikes on mass rides like the 5 Boro but all the trikes have been from out of town.
 The main losses are drag and, at low speeds, friction.A velomobile (enclosed bicycle or tricycle where you lie back) mostly solves the former. The effort of a light walk moves you at about 30km/h on the flat (but slightly slower than walking on a steep uphill).Steel rails would make it slightly more efficient again.
 AlbertCory on March 28, 2023 Wouldn't that be a simple mod to a recumbent bike?
 Honestly, this is the first time I've heard that word. Pretty expected that someone came up with it already, in retrospective.
 check out velomobile, recumbent bicycles with a fiberglass shell that can go crazy fast (60km/h is not unheard of).
 And 144km/h is possible, but only for the world record holder:
 vbarrielle on March 28, 2023 60km/h is sprint speed for elite cyclists on road bikes, I guess recumbent bikes can go way faster than that.
 Faired can cruise at 60km/h on the flat at similar effort to 25km/h on a road bike. Marginally slower on steep uphill.Unfaired won't have you going much faster, maybe +5km/h on the flat and -3km/h on the uphill.
 Turskarama on March 28, 2023 At high speed on flat ground aerodynamics matters significantly more than weight, so velomobiles tend to be a lot faster.Uphill is a different story.
 lmm on March 28, 2023 I hit 90 km/h on my recumbent as a fat bloke loaded up for touring. It was on a downhill though :).
 AlbertCory on March 28, 2023 I see them on the street fairly often.
 The idea is older:
 fnfjfk on March 28, 2023 In terms of efficiency of bicycles alone, aero frames, deep wheels, carbon fiber.Clipless is also an incredibly significant change, but not as much of efficiency as the others.
 Carbon fiber?As I understand it, reducing unsprung weight (which is not very much for a bicycle with no suspension beyond the tires) can have an outsized effect, but actually reducing weight mostly matters for ascending. For non-competitive cycling, other factors seem like they should be much more significant.A big one, which is banned in most competitive formats, is a fairing. This is much more effective than having a human hunker down and try to be aerodynamic. Even for an upright cargo bike (which is generally extremely heavy), a fairing in front can make a dramatic difference on level ground with no wind.
 Carbon fiber isn't better because of strength, but because it's a lot easier to keep somewhat light while making aerodynamic shapes.
 The most important is carbon wheels. Lowering the weight of the wheels makes it easier to turn them, especially uphill.
 It’s only a slight improvement when accelerating. At steady state, the wheel weight is balanced out (half moves backwards, half moves forwards).GCN have done some non-scientific experiments on their YouTube channel on this.The biggest benefit to carbon wheels is you can make them deeper for less weight penalty (vs aluminium) which gives you a significant aero benefit.
 tpm on March 29, 2023 It's also very stiff so less power is lost due to the flex of various parts.
 Which is great if one is racing but not so much for long distance riding or riding for the joy of it. Most riders are not racing at any level where it makes a difference. A well made steel frame is a joy to ride. They are incredibly comfortable and track exceptionally well, unlike stiff frames.
 r00fus on March 28, 2023 Recumbents are noticeably more efficient than uprights. In fact any tech or method that's been banned by UCI should make bikes even more efficient.
 kitkat_new on March 29, 2023 carbon fiber is a lot less efficient regarding manufacturing though, compared to aluminum. The difference is even bigger with respect to steel or the life time of the materials
 swyx on March 28, 2023 > the source cited for it being the most efficent self-powered means of transportation is from March 1973what was the source please? ive actually tried to track this down for the steve jobs quote but couldnt find it
 I had saved the chart here, Google reverse image search led me to this article https://streets.mn/2014/05/22/chart-of-the-day-travel-effici... which says it's from Scientific American.There were a few other hits as well. This one mentions the Steve Jobs quote and corroborates "Scientific American, 1973" https://www.smestrategy.net/blog/using-the-6-thinking-for-st...
 Only on flat smooth surfaces which are a relatively recent invention. Take them on any natural environment and it falls very quickly below walking.
 The difference between riding on grass and riding on a dirt trail is VAST - grass is like 3x worse; but when that dirt trail turns into a mud trail, the grass is better.
 Humans made trails by walking for eons before roads were envisioned. Maybe for a chariot you need a proper road, but a human made trail is just fine for a bicycle.
 Not only just fine but often times way more fun!I rode my mountain bike A TON as a kid, gave it up for the more "prestigious" road cycling as an adult, but maybe 2 years ago bought a mountain bike to ride with my kids.My goodness it took about five minutes on a local trail to feel like that same little kid I was back in the day, the feeling of speed, focus, and flow. There's nothing really like it for me, as it puts me square in the moment.
 sebazzz on March 29, 2023 I hope you're not implying that people in countries with hills don't use a bicycle because that's not true ;-) Check Denmark and Sweden for instance.
 Denmark doesn't have hills. It might have "hills", but not real ones. The same goes for the inhabited parts of Sweden.Colombia could have been a better example, they have real mountains and people over there do use bicycles to do their thing. Granted, not a great percentage of the population does it because you do need to be really fit in order to handle 10% slopes, but of those that do you might get future Tour de France winners.
 Egan Bernal already won in 2019 (and before that Nairo Quintana was second in 2017).
 Yeah, I was thinking at Bernal when writing my comment. As far as I know he used to bike to school when he was a kid, and he wasn't living in the flat areas of Colombia.
 wiredfool on March 29, 2023 The record for the Tour Divide is about 13 days for 2700 miles from Canada to Mexico down the Continental Divide.
 Back in the 80s Steve Jobs cited this fact in an interview and used it for one of my favourite metaphors: A computer is a bicycle for our minds.
 And, in the very very long term 200yrs+, it's one of the few truely sustainable forms of transportation.
 I think it is closer to 9-10 times (on level asphalt road on a "normal" bike) although it heavily depends on some factors like speed, type of bike and your proficiency, terrain and type of ground.Riding a bike is most efficient at a certain speed and becomes less efficient very quickly as you get faster. So when I mean 9-10 times more efficient, I mean a person walking at a comfortable speed vs cyclist riding at a comfortable speed (on relatively level asphalt road).
 Steve Jobs studied movement efficiency, and that’s was why he called the Macintosh a “bicycle for the mind”
 "studied" is a strong word. he read an article once and then talked about it for the rest of his life because it suited his pitch. i doubt he cared about the scientific veracity
 man, Jobs would have killed on VC Twitter, huh
 Recumbent bicycles in particular.
 Not sure if this is common knowledge by now, but one of the mind blowing things about this blogger is he writes these WebGL interactions, seemingly by hand, no framework. Like, best I can tell, keying in the vertices. See https://ciechanow.ski/js/bicycle.js
 I love his articles; the one on lenses truly helped me understand how they work at all https://ciechanow.ski/cameras-and-lenses/
 I'm always in awe of everything he produces. I read somewhere that he uses helper scripts to generate some code, but it's still all manual labor. It's breathtaking.
 I'd be very interested in a meta blog post on how these awesome interactive visualizations are made!
 They are available as commentary articles on his Patreon page. Quite insightful, so feel free to give some support and access these.
 danw1979 on March 30, 2023 That might explain why he “only” does 3 or 4 articles per year. He must be typing flat out.
 I always find it interesting to think about bicycles and just how recently they were invented.Compare bicycles with steel making, for example. Steel making happened thousands of years ago. The modern bicycle was what - under 200 years ago?Bikes seem like such a primitive technology, and yet as this article demonstrates, it takes a lot of engineering to design even primitive products.It makes me wonder how many other simple or primitive products are out there which have yet to be discovered.
 Bikes benefit a lot from pneumatic tyres, pressure pumps, smooth asphalt (not cobbles), precision engineering of chains, chemistry of oils and lubricants, rust-proof steel, rubber brake pads with compounds that last long enough and resist rain, spring steel for suspension, cables that don't stretch. Without those things you get a wooden boneshaker hobby-horse, large, heavy, energy inefficient, incovenient: https://duckduckgo.com/?q=hobby+horse+victorian+bike&t=ffab&...(And internal combustion engines; how are you going to distribute them around the Roman Empire by the tens of millions without trucks or ships?)
 > Bikes benefit a lot from […] smooth asphalt (not cobbles)Bicycle riding societies were some of the more vocal proponents on paved roads (predating the automobile):
 And now of course some of the most prestigious races in the professional cycling world are across predominantly cobbled roads as a form of torture for those racing.
 Also lots of competition on non-paved roads:
 As a former (and not great) CX racer, this sport should not be talked about, as it's a cruel beast to those who dare and try.(Kidding, of course, it's a wildly entertaining form of racing)
 loeg on March 29, 2023 And MTB and Gravel racing, of course.
 On a well-made steel crossbike or touring bike, rough roads and dirt roads are a downright joyful experience.
 sasawpg on March 29, 2023 With the most exciting Sunday in the entire year of racing coming up!
 Khoth on March 28, 2023 To expand on one of those things - bike chains get slightly longer as they wear out. Once it's about 1% longer than it started, it looks about the same as it always did, but it's starting to damage the drivechain and you need to replace it. An ancient Roman blacksmith has no hope of making a chain with anything like that level of precision.
 I believe you only have this problem if your bike has gears based on a set of sprockets (different size chainwheels and a derailleur to move the chain from one to the other).In Europe (Holland in particular), people ride single gear city bikes (or internally geared hubs) for decades without replacing chains or cogs. When you only have one chainring and one cog, they wear along with the chain, and it takes a very very long time to encounter problems.It's when you have the sprocket cluster with multiple cogs that are not all wearing equally, that you get problems. Or often the problem on geared bikes doesn't appear until you replace your worn chain and the new chain no longer meshes well with the cogs worn to match the old chain.
 Nope, with single speed/hub gears chain wear is still a problem, it's just that they're less sensitive to it and there's fewer parts to replace. When the chain gets longer it gets loose, but it has to be very loose indeed to fall off or skip on a single speed. With a derailleur setup there's a tension arm with a weak spring so when the chain wants to skip that tension arm lets it. Derailleur setups commonly have some cogs with fewer teeth than single speeds so the problem is more obvious. Also, often derailleur cogs are aluminium while single speed ones are steel (not always!).Typically a safety bike will get through 3-5 chains before needing to replace the rear cog, and many more before replacing the chainring(s). But Pinion gearboxes in the bottom bracket often run small chainrings that are similar in size to the rear cog, and I suspect they need to replace both rather than just the rear one.
 I ride a bicycle with a hub gear as my main form of transport. About two years ago, I noticed the sprocket (rear cog) was getting very worn, so I removed it so I could reverse it and let it wear on the other side of the teeth (standard procedure for this sprocket to extend the wear life). But I accidentally put it back the same way as before and didn't notice until recently when I changed the hub oil. I had no problems with the chain skipping, despite the heavy sprocket wear (although it's now worn to the point that I no longer feel comfortable letting it wear on the other side of the teeth, so I'll have to buy a new sprocket). But you are correct that the chain wears more than the sprocket; I've already replaced the chain a few times.
 https://ibb.co/0sJx4SN (new cog on the left, old on the right)I'm not saying you should do this. And Rohloff strongly suggest you don't do this I'm just saying that you can do this.
 askvictor on March 29, 2023 The other factor is that single-speed/hub-gear chains are wider, so tend to last a lot longer.
 jen729w on March 28, 2023 Or in any flat hipster city. Melbourne (now Canberra) representing!I ride my single speed (not fixed) every day. It’s my most beloved possession.
 mardifoufs on March 28, 2023 Wouldn't the chain still need to be quite intricate and pretty hard to make even then? Though now that I think about it, you could probably make it in a way similar to chainmail, since tight tolerances aren't actually that crucial (the results would suck, but only compared to modern bikes). Though the other parts might be just as hard to make and especially to fit together (the bearings, the gearing for the chains...)
 Bronze bushes work for bearings (still needs a lathe/ but not ball bearings). Chains can be belts of horsehair (or any civilisation with wire, tube and sheet metal can make a modern chain) or a treadle works okay. Spokes can be wooden.The main limiting factor is probably the pnuematic tyre and smooth roads.
 loeg on March 28, 2023 Yeah. The vast majority of parts on a bicycle are the individual links in a chain. Manufacturing these to sufficient tolerance is quite challenging.Romans might have been able to do shaft-drive. Or Penny-farthings (direct pedal-wheel drive).
 cjmcqueen on March 29, 2023 Chains don't stretch, they wear down. When measuring a chain, you measure the distance between links to see how much material has worn away. The links don't actually get longer from stretching.
 you would have used leather belts. it would have been a pita, they stretch pretty fast...but its feasible I think.
 You don't have to use chains though, you can have pedals on the front wheel, like the original bikes(velocipedes), or not pedal at all, just push yourself on the ground (balance bicycles)
 Penny farthing bikes are death traps. Bikes that have similarly sized wheels with pedals on the front wheel aren't practical enough to be better than walking. Bikes without pedals are also not practical.
 They were both more efficient than walking. Humans will put up with death traps if it means more efficiency in transportation (just look at car fatalities). The only reason they didn't took off faster was the lack of roads. And by the time we had tarmac roads bikes already evolved to have chains and read drive.Watch a kid on a balance bike and tell me how it's not practical, lol. A 4 year old can bike around a whole park in seconds.
 tpm on March 29, 2023 also there are other ways to transmit power than a chain (belt, shaft etc).
 Alex3917 on March 28, 2023 The key invention that made them possible was ball bearings. This is why the modern bicycle and the modern car were invented within a year or two of each other.
 ...and roads, which were created for use by horses and carraiges.
 B1FF_PSUVM on March 28, 2023 Yep, 90% materials, and so are other things like windsurfing, paragliding, etc.Very little of the "modern stuff the ancients didn't figure out" could be done without modern materials.If dumped back in time, maybe you could make rent teaching swimming or doing accounting. Medicine would probably be too dangerous.
 Yeah. Surfing is a great example of a Stone Age sport that has been radically changed by Space Age technology. Koa wood gets you a longboard that is hard to steer and can only surf long smooth waves. The modern surfboard is very much born out of California's aviation industry and its fixation on light, strong materials and aerodynamics. Surfing Pipeline is only possible with modern plastics, fins and shaping.
 Well, I've got a bike from the 30s and it's perfectly fine for everyday riding. While I agree that most of those things you listed are valuable and convenient, good enough is often just good enough. Like I've got no use for any cables and I don't need precision engineered chains.
 A parallel thought is that the first airplane is the product of bicycle mechanics and not railway or automotive mechanics. As others pointed out, there are a lot of necessary technologies like rubber, bearings, lubricants, sprockets and chains that need to be developed, but there is also something very elegant about bicycles. If you start to mess around with a 70's era road bikes you get a sense of just how perfectly everything needs to fit together and how everything affects everything else. (You see it more clearly in older bikes because you need to deal with non-standard parts). I think I learned more about bicycles from the royal pain of a 1982 Peugeot than anything else. This is not to say that a car doesn't have similar complexity, but the use of chemical fuel and 4 wheels masks how the tunings fit together. With my current bike there is a serious difference when it is perfectly tuned.
 Agreed. Bicycles are kind of a miracle of seeming simplicity hiding a ton of important developments of the industrial age. 99 Percent Invisible did a recent episode on just this topic: https://99percentinvisible.org/episode/the-safety-bicycle/.
 A thought:The invention of the bicycle came at a similar time like engine driven vehicles. Before those became popular, the direct competitor for bicycles (one person transportation) were horses.There might have literally not been a need to invent a bicycle as horses fulfilled the same purpose and had the advantage that they fared better on the back then nearly non-existent infrastructure.Also: a single person transportation vehicle was not something a lot of people needed in their lives. You needed something to move stuff, but the demand to move single people daily came into existence with the dawn of big cities.
 It takes a LOT more calories to power a horse than a biker.
 On a cretan mountain path with before christ technology?
 There's a reason that horses were the fancy sports car/military tool of the animal transport world. They eat a lot, break easily, and don't last long.People used oxen, donkeys, llama etc way more than horses. And the Chinese invented wheelbarrows and used them extensively rather than using draft animals. They often use bicycles much the same way as wheelbarrows now, and rich people often find that amusing (possibly because a KMart bike is a toy, a Chinese bike is a workhorse).
 The production of quality steel isnt thousands of years old.Yeah they could produce small items - but to make the steel of the quality needed for bicycles is pretty new - the past 150-200 years with the Bessemer process
 They could've just made them out of carbon fiber composites before /s
 The timing of the invention of the bike is discussed here: https://rootsofprogress.org/why-did-we-wait-so-long-for-the-...He settles on general economic and cultural factors. Experimentation requires there to be enough people with spare time and resources to play around with things with no immediately obvious payback.
 I guess perspective makes it a lot less surprising that the first airplanes were made by bicycle manufacturers.
 Don't even get me started on airplanes though - there was only 66 years between the first airplane (Wright Flyer in 1903) and the moon landing (1969).Disclaimer: that's of course a cool anecdote on the surface, but rockets have been around since the 13th century so they're two mostly different technologies.
 Are rockets and planes related? Quite different requirements regarding aerodynamics and propulsion.
 It's all the same, just that the density of the fluid the vehicle is traveling in changes.
 So a submarine is the same, again?Key development for flight: Wings which carry the plane. First planes didn't even have an engine (besides human)Key development for rockets: Strong powerful engines to escape gravity. Aerodynamics matter relatively little, mostly for heat control.I don't know how related the development of jet engines and rocket engines was. Of course things like the Space Shuttle, which has some airplane-like aerodynamic steering tie both together ...
 We're playing a bit fast and loose with our phrasing here if we want to split hairs about the development of these technologies.Powered, navigable, human flight existed before the development of wings.The early rockets mentioned above weren't for human flight, nor for spaceflight. Rockets were developed to be terrestrial weapons, not to propel humans.Rocket engines and turbine engines are both a type of jet engine. These engine technologies themselves weren't developed together because one was developed to make airplanes go higher and faster, and the other was developed to stab people with arrows better. If what we're really talking about is "human flight", then rockets and turbine engines were both used to propel humans on airplanes before anyone started considering spaceflight.And then when humans did consider spaceflight, humans were developing space planes and tubular orbital rockets at the exact same time. The space shuttle was far from the first plane to operate at heights where the control surfaces no longer work. The X15 actually flew 2 years before Vostok 1.The people developing human flight were always interested in going faster and higher. The technologies they experimented with were intermixed the whole time.
 Thanks for the long response really appreciated!
 samstave on March 28, 2023 You will be amazed to know that the Ball Brothers, who invested the Mason Jar/Atlas Jar, and perfected canning and soups... is also Ball Aerospace - who makes super-high end space components for the MIC, black projects, skunkworks, NASA etc...All from the Mason Jar.https://www.visitmuncie.org/a-legacy-etched-in-glass-the-bal...(also "Aliens")
 I always loved the scene in HBO's Deadwood when the first bicycle comes to town and everyone gathers to watch someone try and ride it.
 The safety bicycle (chain, pedals in the middle) is about a decade newer than the car (under 150 years), although they hit mass production within a year either side of each other depending in how you define it.
 Ball-bearings? Primitive?? Surely you jest!
 > Bikes seem like such a primitive technology, and yet as this article demonstrates, it takes a lot of engineering to design even primitive products.Very strange. I get that we take things for granted if they've been around forever (ie. since before we were born). But I never considered bicycles "primitive". What makes you think that? Is it because they don't need electronics? What is a non-primitive transport technology?
 No shit, you can make an airplane if you know your way around a bicycle as the wright brothers demonstrated. They were bicycle mechanics originally.
 Bicycles are a relatively new invention because they require roads/flat paths which are also a relatively new occurance, and came about due to the widepread use of horses and then carraiges for transportation.A bike at any other point in human history would have been completely useless trying to traverse natural terrain.
 The modern "fat bike" would be (is!) quite good at traversing a variety of natural terrains where humans live, without roads or paths/trails.
 "Roads? Where we're going, we don't need roads.". o O ( Now if only 18.8 MPH were enough to activate the flux capacitor. )
 Mountain bikes do not require roads or flat paths; they work fine on trails (hence the name "mountain bike"), which have existed since large animals evolved.However, mountain bikes arguably require even more technologies than other bicycles, especially for suspension and brakes (MTBs pioneered the use of disc brakes on bicycles).
 Pshh, I know how to ride a bicycle, why is ciechanowski writing an article about riding a bicycle?!Holy moly!! I didn't realize I didn't know how I actually ride a bicycle!!Obligatory sound track for this excellent post:
 You probably know this...but the song is not about a literal bicycle...it's about Freddie being "bi". I only say this because it took me too long to realize that.
 Dang, you beat me to it, I was busy inflating my tires to 120 psi.
 Go tubeless!
 When I first started MTB in 2020... I tried to inflate my tubeless rear tire to 60psi once, because that was the "max pressure" written on the sidewall.There are times you are incorrect, and wow, there are times you are very very wrong. They should make tubeless sealant in blood red just for fun.
 Similarly, a Honda Fit with tires inflated to 90% ofthe sidewall's max pressure is /very/ fuel efficient, but you better plan on replacing tires pretty often. After a few potholes, usually.
 What a phenomenal explanation of forces. I wish I had this when I took my first physics class in college. I thought it was particularly excellent at explaining "how much the wall knows to push back", which is something I didn't quite grok (but just accepted) back in college:> You may wonder how the wall knows how much back-force to apply, so let’s look at the interaction between these two objects up close and in slow motion. As we apply the force, the box actually starts accelerating into to the wall, pushing its surface to the right:> As the box moves to the right, it compresses the molecules in the wall, which create a spring-like force that pushes the box back. If that force is too small to balance the pushing force, the box will continue to move to the right, which compresses the wall even more, creating an even larger push-back force.
 Awesome stuff as always. Don't forget to support his patreon: https://www.patreon.com/ciechanowski
 You will love the interesting video, "Most People Don't Know How Bikes Work" by Veritasium - https://www.youtube.com/watch?v=9cNmUNHSBac
 Worth watching but for folks who want a TL;DW:
 It's actually linked deep in the article.
 I saw the domain name "ciechanow.ski" and immediately upvoted it even before I opened it. The quality of posts by Bartosz is just next level.
 https://ciechanow.ski/mechanical-watch/ this is still my all time favorite blog post.
 Same. The blog is just incredible.
 Right? His posts are an equivalent of new GTA releases when I was a kid.
 Same here. What an amazing content he makes.
 i'm a simple man: i see ciechanow.ski, i press "like"
 Another great interactive explanation.I wish physics teachers start using geometric product of vectors, instead of the cross product. This allows forces and torques to be combined into a single concept "Forque". Really, translations are just rotations around infinity and rotations are just composition of two reflections. If we allow the algebra to take care of rotations, physics becomes a lot simpler.
 Wait until (all) teachers start using AND SHARING really well crafted prompts for teaching aides /r/coolguides lesson material.There should be a central repo for all subjects where topics can be looked up to find a guide like this one - and the prompt is public, with revision edit logs (like wikipedia) such that a standard agreed upon response can be adopted by acedmia for explaining a particle concept.Let the acedemics expand upon, tangent from, deep dive into the sub components of each topic.The University.ai
 I've always loved that little fact about having to initially turn the handlebars the opposite way to initiate a turn.It's pretty much impossible to believe without thinking it through, and yet everyone naturally intuits it.It's one of my favourite examples of how the brain can just 'feel' forces and make the right adjustments incredibly fast. So amazing.
 Countersteering is convenient, but not required. A bicycle and rider are not a single rigid body. You can simply lean to one side and you'll have to steer in that direction to keep your bike under you -- no countersteer necessary.I am not saying people don't countersteer, only that it isn't necessary to make a turn.Also, bicycles aren't motorcycles where the weight ratio between rider and vehicle is swapped.If you don't feel like clamping your handlebars so they only turn one direction, try this: coast along a straight line (and outdoor basketball court is great). Then pick a direction and just lean that way. You can absolutely keep your wheels on the line until you turn in the direction you picked, with no countersteering necessary.This "fact" came about with a video of low skill riders who can't manipulate a bike very well, or don't know what it is they're doing when they do it.
 Veritasium did a video where they stopped him from counter-steering and couldn't steer anymore. https://www.youtube.com/watch?v=9cNmUNHSBacHe might be wrong, and just didn't know enough, but he is usually researching his videos very well and I would be surprised for him to be wrong about this.
 What he demonstrated first of all is that you simply can't ride a bike that prevents the steer from turning in one direction. A bike continously falls to one side or the other, which gets corrected by steering in that direction to put the contact area back under the center of mass. This happens not necessarily through the rider's (conscious) action, even a bike with no rider does it to some extent, but in all cases it requires the ability to turn the wheel assembly freely around the steering axis.IMO that means the bike in the video demonstrates failure to keep basic balance even before it gets a chance to demonstrate failure to turn properly.
 LanceH on March 28, 2023 just try it. roll perfectly straight and lean to a side. It accomplishes the same thing as countersteering, which is to put weight on one side of the bike, so when you turn that direction, the bike gets under you and you don't fall.
 That's literally what they did in the video, I recommend you watch it. The issue is: you think you can just lean on the side you want, but you can't without counter-steering, so they devised a bike that literally does not allow counter-steering: you can't take a turn at all.
 Because of the geometry of the front fork (rake and trail), if you lean to one side the bars will initially turn in the opposite direction. It's still countersteering. If you ever ride a bike where this geometry is wrong, which is difficult because it's so necessary, it's very different to ride, and you'll struggle to ride it non-handed.
 IshKebab on March 28, 2023 I'm not sure your line method proves much since the countersteer could be very subtle. However I think you're still right. Countersteer makes you start to fall faster, but it clearly isn't necessary to make you fall because you do that anyway!Next time I'm on my bike I will try it anyway.
 No it's not necessary in the strictest sense of the word, but counter steering achieves higher turn speeds, offers better control and precision, requires far less physical effort, and works at nearly every speed. I can't think of many pragmatic reasons not to use counter steering outside of just screwing around for fun.
 This effect has a big play on motorcycles. Riding a bicycle is considered prerequisite knowledge for learning to ride a motorcycle, largely because of this counter steering. One thing that is more pronounced on a motorcycle is that counter steering only occurs while the bike is moving at speed. As in, you only counter steer a motorcycle above ~10mph (higher for some motorcycles). It's really cool to think about how intuitive this switch is, almost everyone picks it up quickly and it becomes second nature.
 Countersteering applies at all speeds, it's just that balance plays a bigger role at lower speeds. The wikipedia article on countersteering goes into this a little bit.
 Gracana on March 28, 2023 > As in, you only counter steer a motorcycle above ~10mphI don’t believe that this is true. Can you explain the physics?
 Go play with the animation in the article after the text> In this next demonstration, the wheel is spinning around the red axis, and you can also apply a torque that rotates the wheel around the green axis:At highway speeds on a motorcycle, this effect is very strong.But at low speeds in a parking lot, any gyroscopic effect of the slow wheels is nothing compared to a 250lb+ motorcycle.Bicycles work the same way when you're moving very slow.
 helaoban on March 28, 2023 Ride a motorcycle for 5 minutes and you'll believe.EDIT: To answer your question more directly, you are steering in one direction to initiate a lean in the opposite direction. E.g. if you are attempting to turn right, you first steer left which generates force in a left-sided contact patch in the front tire, which causes the bike to lean right. The bike then assumes a stable right lean angle (you have to do some work with your body, but the bike naturally wants to do this), and the front wheel comes back into alignment, and you are now turning right.A good explanation: https://www.youtube.com/watch?v=PgUOOwnZcDU Some more detail: https://en.wikipedia.org/wiki/CountersteeringEDIT 2: I misread your point. You are correct, counter-steering still applies at low speeds but the "feeling" is masked by lack of momentum.
 I have one. I still countersteer to turn in parking lots.
 Yeah, but you quickly counteract with direct steering after you initiate the turn, so the overriding sensation is one of direct steering at low speeds, even through the physics is the same. This is what I think most people are referring to when they talk about high speed / low speed steering.
 closeparen on March 28, 2023 In parking lots. It's a different steering regime at lower vs higher speeds.
 The "counter steer isn't real" debate about to start again!
 The debate is whether countersteering is something you have to consciously do by turning the steering column ("yaw"), or whether it's an automatic effect of pushing/leaning down on the side you want to turn toward ("roll")."countersteering isn't real" because "steering isn't real", cycles at speed turn by leaning/rolling, not steering/yawing.
 Countersteering and roll are not mutually exclusive. The countersteer generally happens when steering whether you think about it or not. If you know about countersteering, you can practice it to make emergency turns.For roll, Leaning in the direction of the bike is actually a bad habit (but it'll be fine on most road turns)It turns out you want to lean the bike, and lean/shift your body in the opposite direction. This keeps center of mass above the wheels.For example, the pro motorcycle racers with their knee an inch off the ground,they're leaning their body weight away from the turn, away from the ground. Meanwhile their bikes are leaning crazy hard.That style of leaning is important for fast descents, or switchbacks, particularly switchbacks. Eg: "MOUNTAIN BIKE TIPS: CORNERING WITH CONFIDENCE" (start at 1:45) https://youtu.be/GFKPtEzE4xw
 helaoban on March 28, 2023 If you need to quickly swerve out of the way of an obstacle you push hard on the handle and you will immediately initiate a turn (you could just as easily say that your are initiating a lean). It's also well understood that handle bar input allows you to increase / adjust the lean mid-corner. I ride and never knew there was a debate about this.
 Also worth mentioning bicycle related is the lifework of Sheldon Brown: https://www.sheldonbrown.comNot fancy looking, but very interesting.
 Sheldon Brown is a great resource for bike information - lots of no-nonsense advice and explanations though it is getting a bit out-of-date now since his death. A particular favourite of mine is his chain cleaning method: https://www.sheldonbrown.com/chainclean.html
 That would be something I'd personally consider out-of-date with modern chains. Apparently that makes me a "Lazy, careless cyclist" as I would never use grease on a chain. Nor would I ever follow this insane method of cleaning a chain.Guess I'd consider myself to be an efficient cyclist, which may be construed as "lazy" by some.edit: reading onward, he claims "Serious cyclists, who value performance..". I wonder what he considers "performance", because it sure appears he didn't consider or measure drivetrain efficiency.
 Knowing how much of a PITA even modern in-depth chain cleaning is with solvents... I can't read that article as anything but satire. Even with old roller designs, an overnight soak in paint thinner followed by an ethanol bath should get the whole thing close to bare metal. Maybe the disassembly is specific to getting roller grease applied properly, unlike how he mentions manufacturers just dip the chain in a homogeneous lubricant? I'm surprised Brown didn't advocate for chain waxing over using grease for performance and maintenance reasons.
 I hadn't actually read the chain cleaning page before but I did read his page on chains, which to an extent is contradicting with his chain cleaning page:"New chains come pre-lubricated with a grease-type lubricant which has been installed at the factory. This is an excellent lubricant, and has been made to permeate all of the internal interstices in the chain. The chain and this lubricant need to be warmed during application.This factory lube is superior to any lube that you can apply after the fact -- well, unless...see below."Hard for me to tell what is original content vs. new. It has been empirically demonstrated that factory lube and grease are considerably inferior when it comes to drivetrain efficiency (performance) compared to a wet lube, which is less efficient than either dry lube or wax (with or without additives).I've waxed chains for a while in the past but stopped a couple years ago. I now do a "good enough" quick clean of a chain using an undiluted degreaser, rinse with water and a final rinse with isopropyl. The whole process takes 5 minutes and the chain is clean enough for new application. Not clean enough for waxing, you'd want to throw in a solvent before ethanol/isopropyl, but good enough for wet/dry lube. I've no science to back longevity of chains following above procedure, I generally swap between 2-3 chains during a season to keep wear reasonable and then start fresh in the fall before indoor.
 That chain cleaning page is satire, or at least that's how I read it.