Velocipedia | Hacker News Reader

Velocipedia

gianlucagimini.it

430 pointsmodernerd107 comments

The first bike is missing its chain stays, the bars connecting the bottom bracket to the rear axle and the ends of the seat stays. Wikipedia has a nice diagram with the names of all the parts of a bicycle [1].

There are real bike designs that have a monofork (a one-sided fork, e.g. the Cannondale "lefty"), a monostay, or a solid body instead of top & down tubes (e.g. many folding bikes or the extremely aero Ventum One [2]). The Giant Halfway [3] folding bike has all three features!

[1] https://en.wikipedia.org/wiki/File:Bicycle_diagram-en.svg

[2] http://www.slowtwitch.com/Products/First_look_at_the_elusive...

[3] http://www.giant-bicycles.com/en-in/bikes/model/halfway/1905...

Another fun fact about chain stays is that modern bikes are not symmetrical on either side of the vertical plane. The drive-side chain stay is noticeably thicker on the right hand side (drive side) to deal with the very high stresses in this area.

This photo shows this asymmetry quite clearly: http://velonews.competitor.com/files/2010/09/IB2010_cervelo1...

That looks to me like the non-drive-side is thicker, rather than the drive side.

It also depends on the bicycle. I've got a '53 Schwinn three speed that's made out of what seems like gas pipe and it's perfectly symmetrical. A number of my old steel road frames look similarly, and so does my current titanium road frame.

That's a good point! I completely got it the wrong way around and didn't look at the image properly before posting it. The non drive side must be thicker because of the torsional force on the frame when pushing on the pedals. Too late to edit my post!

What is the purpose? To reduce torsion of the rear axle?

To form the triangle that locates the rear axle. Without it, the seat stays (?) would flex and break.

Most bicycle frames are two triangles sharing the seat tube, making it strong and rigid.

But at least that bike is theoretically possible if it was built rigidly enough that it didn't flex too bad.

The interesting thing was that many of the drawings were not physically possible at all, like connecting the chain to the front wheels, or some other bizarre mistakes.

> But at least that bike is theoretically possible if it was built rigidly enough that it didn't flex too bad.

True, but a construction would stand a good chance of being too brittle and subject to catastrophic failure during riding involving changing loads (or bumpy roads).

Connecting the chain to the front wheel is certainly possible. For example, take a look at the Cruzbike http://www.bentrideronline.com/wordpress/wp-content/uploads/...

the first thing i noticed wrong with the first bike was 'oh my god that's a terrible placement for brake levers!' and only after I noticed the missing chain stays haha.

As another example, here's a 19th-century bicycle design without a chain stay. Not necessarily a good design, but it was actually built and ridden: https://commons.wikimedia.org/wiki/File:BicyclePlymouth.jpg

bicycles facing left: 75 %

bicycles facing right: 25 %

That's unexpected. For some reason I'd think more would be facing right than left, and if I were to draw one it would probably be facing right too. I don't know why but it seems to feel more "natural". I just Googled images for "bicycle" and 32 out of the first 40 were facing right.

I noticed all the renders were facing right as well, even if the original drawing wasn't.

I wonder if the dominance of right-hand-traffic countries is related.

Most traffic signs and signs on bicycle roads have bicycles facing left, maybe that's why?

https://rowerowapila.files.wordpress.com/2013/05/wp_000139.j...

I'm going with this one as well.

Most other reasons I could think of would suggest opposite results than the distribution from these drawings.

Next suspicion would go to some "hidden" variable common to the individuals that drew the sketches.

I would draw it facing left and I think that's because of the way I learned to mount a bike: the bike-stand is on the left side so you need to have your last foot on the ground on the left side in order to pull it up.

Nice explanation! I'd also paint it that way and thought this was because bikes on advertisement materials are usually shown that way around.

This. It's the way you approach a bike to mount so that's the way it looks inviting in advertisements too. I'm not sure if "stand fixed to left side" is a rhs traffic thing or something global?

Same with horses, boats and airplanes... and yes, I think in all these cases it's the global convention.

Including England, Australia, Thailand, Indonesia, Japan, etc?

Yes, this is my guess too. Are all bikes mounted from the left even in areas with left traffic? Haven't thought about that before.

I believe this goes all the way back to horse-mounting - mounting from the left is easier, as your primary hand weapon (sword, mace, club, whatever) is likely to hang at your left side, where you can easily reach it with your right hand; this makes mounting from the right considerably harder, as the weapon gets betwween . (It would probably reverse for left-handed fighters; this had very little impact on today's bike mounting and kickstands, however)

>the bike-stand is on the left side

Obviously that's just if the bike is positioned facing left.

Nothing inherent about it, you could just as well mount a bike facing right, and it would be on the other side.

A bike stand is only attached to one side of the bike. So it's always on either the left or the right, no matter which direction the bike is facing.

That's compared to the bike -- I meant compared to the road.

Compared to the bike yes, the stand is on a specific side (e.g. left) -- but how/why would that affect whether you draw the bike facing to the right or left?

My guess is, it's to do with left-to-right reading/writing.

but that would suggest opposite results no? write from left to right > bike going from left to right (facing right)

Most photos of bicycles are facing right to showcase the drive side - all the drive-train components like chainrings, derailleurs etc.

This is definitely the case in photos. When I draw a bike it's always pointing to the right, because that's how most pictures I see/take are.

Movie convention... the cowboy rides the horse to the right when leaving, and to the left when arriving.

It’s a video game convention as well.

Maybe because we read left to right. Pointed to the right looks like progress. "Good" charts go "up and to the right."

Tangentially related:

Which Way Did He Go? Lateral Character Movement in Film https://www.youtube.com/watch?v=Ys8-a0yD-MM

Hmm, facing left would look more natural to me, but indeed, Google images shows most bicycles facing right.

OTOH, most cars seem to face left.

My guess would be that people draw left to right, and also start drawing the part that is simplest. If you look at some of the drawings it seems that people get confused about how the gears and the rear wheel connect to the rest of the bike, while the front wheel and handlebars are more often correct.

I think I'd draw it facing left because I'd draw the front wheel first, and since I'm used to writing left-right, the back wheel would go to the right of it.

For the psychology research he mentions, there is a paper, Rebecca Lawson, "The science of cycology: Failures to understand how everyday objects work", https://www.liverpool.ac.uk/~rlawson/PDF_Files/L-M&C-2006.pd...

> The participants were given a single sheet of paper, folded in half. The bicycle drawing task (see Figure 1) and the forced-choice task (see Figure 2) were on the top and bottom of the first side, respectively, and a questionnaire was on the other side. First, the participants were asked to rate their functional knowledge of bicycles on a scale from 1 (“I know little or nothing about how bicycles work”) to 7 (“I have a thorough knowledge of how bicycles work”). Next, they were asked to draw the pedals, chain, and extra frame onto a sketch of a bicycle (see Figure 1). Then, they were asked to select which of four alternative pictures was correct for the bicycle frame, pedals, and chain (see Figure 2).

> Over 40% of nonexperts made at least one error in both the drawing and the forced-choice tasks (see Table 1). In this and the subsequent experiments, error scores were almost as high on the forced-choice task as on the freehand drawing task, indicating that production problems were not the primary cause of people’s deficiencies.

This is a great art project, and I especially enjoyed some of the stats at the end. The motivation seems to be thus:

"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."

I wonder what rendering software was used to generate the drawings?

From the gif in the article, looks mainly like just some clever (and impressive!) Photoshop. Reading on my phone, I suspected Keyshot and a 3D modeling program at first, so that was a big surprise!

I couldn't draw a bike until I started fixing them. And I rode every day :/

Besides that, the renders are beautiful.

For me the most impressive thing is - these are not renders. (S)he had done it in photoshop.

Renders also mean drawings. Scott Robertson's book "How to render" does not explain how to press the render button in Blender, it explains how to actually draw (render) a concept art.

We already had grammar nazis. I guess it's time for the semantics nazis!

How dare he correct someone who already tried to correct someone else (and was wrong). Why does calm clarification threaten you?

I truly believe that the renders -> photoshop clarification was genuinely more useful than the 'renders can mean any kind of drawing (even though it's clear from context that the writer meant computer 3D rendered)' clarification. Not that the second one was useless, but calling the photoshop point 'wrong' is way over doing it.

> renders -> photoshop clarification was genuinely more useful

Except 'the clarification' is wrong. If you have a render, it doesn't mean it's 3D. It can be 3D, 2D, a mixture of both (last is probably the most frequent). It's a render.

This question can be more important than you think, since people may have the wrong expectations when they get a 'render' from the industry. Good post-processing (color balance, a bit of motion blur and other small effects) can work wonders to show off a product (e.g. video-game), while not being so representative of the end result. Which explains then the disclaimers on trailers and screenshots, which are not there to be pedantic.

Anyway, I'm off sending Wittgenstein to the camps.

I disagree that it was wrong. A render is clearly a term with multiple meanings, depending on context, and in the context and audience here most readers will take it to mean 3D rendering . That there is a context where the statements are true does not mean that the statements weren't making the wrong impression in the readers here. Check out the author's reply, clearly indicating that they were surprised at the clarification.

Why should I feel threatened. Check tgb's comment for further clarification.

The fact that tgb "truly believes" the first, and erroneous, clarification was more useful means nothing to me. The first comment was simply incorrect. The impetus was to say someone was wrong. This was corrected by someone else, in a very civil manner, and you called that person a nazi. Grow up and leave meaningful comments or else don't bother.

It's not just that the first clarification was more useful. The first clarification was correct. The comment said the renders are beautiful, obviously meaning rendering in in the 3D rendering[1] sense. The clarification stated that they weren't rendered in that sense because the author used photoshop, which doesn't render in that sense.

Then the second clarification stated that rendering also meant drawing... and while it does, it also has a specific meaning within 3D representations which doesn't really fit here.

Nothing to call anyone a nazi over but the second clarification wasn't needed or useful.

[1] https://en.wikipedia.org/wiki/3D_rendering

"Semantics nazis"?

Quite a roundabout way for describing people that care for the accurate use of terms...

Is assigning random personal meanings to words a thing now? I mean, talk about putting the p...y on the chainwax!

Words are tricky. They don't have one true definition. What's accurate for one, may not be for another. Words have multiple, sometimes incompatible meanings, depending on context of discussion and participants. It's not really about completely random meanings that differ from person to person, but more about slightly different meanings that differ from culture group to culture group.

I see more and more that people attempt to devalue & derail statements made by others by making an offensive remark about semantics, instead of attempting to understand what was said.

It would be convenient if everybody used a single definition book for every word, however we don't live in such a reality. A "semantic nazi" is a person who goes around and tries to convert everyone to use their culture group's definition book. [1]

[1] I want to be clear that in this specific case the "render" definition extension was pointed out in a respectable manner and I wouldn't pin the nazi name on them for it.

Arright, even more impressive :)

These have great metaphorical power for software engineering slidedecks. Not sure whether they best illustrate 'emergent design', 'the difference between a pretty UI and a good UX', or 'the difference between giving the customer what they asked for vs. what they need.'

it's hard to imagine people getting a bicycle this much wrong http://www.gianlucagimini.it/wp-content/uploads/2016/03/Gian...

not that I'd draw it with perfect mechanical fidelity, but there are bicycle defining parts missing there.

That's not very wrong, it's just missing things (rear triangle, drivetrain).

At least you could ride downhill on it (though stopping may be an issue).

I would say it's one of few that could not break as soon you get on :)

It really looks like as a history bicycle, where you used foots to push.

http://i.livescience.com/images/i/000/064/812/iFF/hobby-hors...

Also known as a "Velocipede".

For a lot of people, "bicycle defining parts" probably means "two wheels and a seat", which is what all the drawings have in common.

I wonder what a machine learning algorithm would do with those renders if asked to identify pictures of bicycles, since all the drawings and renders are unmistakably bicycle-ish to people but also not "perfect" bicycles.

For comparison, https://en.m.wikipedia.org/wiki/History_of_the_bicycle#1817_... also has bicycle defining parts missing, but we call it an early bicycle, anyways.

This is exactly the same as in a Brain Games episode where the host had some college students draw a bike, only one got it right. http://natgeotv.com/ca/brain-games/about

Though being biased by this article, I do think I could have drawn one correctly. It's fun to ask peers though, surprising things go wrong. I even saw the double-chained one, surprised by that! (Chain attached to both front and back.)

What is wrong with the topmost bike?

No frame between rear wheel and front chainring. No strength.

But the front wheel is also missing that beam on a correct bicycle.

Edit: implying: if the front wheel doesn't need it, why would the rear wheel?

I would like to see you turn a bike with front-wheel chainstays. Straight-only driving, turns are obsolete! :D

Also, the front wheel is connected to the frame in a very different way than the back wheel: single strong tube, only diverging further on; and there is no requirement for the front wheel to be powered - therefore the front wheel can (and does) move WRT the frame, something the back wheel must not do. Yes, they're both wheels, but that's where the similarity ends; the rest of the requirements are very different.

You can actually turn by leaning in the correct direction. This is actually the usual way to turn if you're no-hand biking.

http://www.wikihow.com/Ride-No-Handed-on-a-Bike

It's the usual way to turn when using your hands too - in fact, you (subconsciously) turn your handlebars the "wrong" way when cornering on a bike (https://en.wikipedia.org/wiki/Countersteering). This is very counterintuitive and discussing it is a good way to start arguments...

I thought that countersteering is only for motorcycles?

But then , cite "The entire sequence goes largely unnoticed by most riders, which is why some assert that they do not do it", end cite, is most probably true.

You definitely countersteer on bicycles too!

No. The effect is, of course, much more pronounced with motorbikes, given the greater mass and velocity - but anything resembling a bike can be countersteered.

Countersteering is becoming more well known know amongst motorcyclists (thanks to more rider training and the internet), but some riders go there whole lives without knowing about countersteering. This is unfortunate because learning to consciously countersteer makes you a much safer and more skilled rider. The same holds for bicycles too I suppose.

Of course - note that this, too, requires a front wheel with two degrees of freedom (although it's possible to turn a no-steering two-wheel vehicle by leaning, the effect is minimal compared to one steerable wheel); front chainstays would prevent this.

Turning would be quite difficult on a bike with one. ;)

Distribution of weight is not equal.

Front wheel is attached to a thick tube that is almost vertical (weight tries to compress the tube), and that tube is attached to another thick tube throught a wide strong pivot that keeps the angle between the tubes constant.

Back wheel is attached to two thin rods at 45 degreee angle. Weight tries to push the seat down and push the back wheel away (to increase the angle). That's why we need another tube to hold the wheel at constant disntance (and to keep the angle fixed).

You could probably make it work by creating similar strong joint keeping the angle between seat tube and wheel rods constant for the back wheel, but why? Hm, maybe to make a bicycle with both wheels turning :)

Sorry for my English, never had to describe bicycles and probably all the techincal terms are wrong :)

Also, the "chainstay" provides rigidity against the tension created by the rider on the top half of the chain, and the force of the wheel pushing the bike forward, which can be prodigious!

PS your English is fine! Only noticed a throught->through typo.

It doesn't really _need_ it; the seat stay could be designed to be stronger, but there's more of your weight on the back wheel than on the front wheel, so the seat stay would have to be stronger and, hence, 'fatter' than the fork.

And, since the angle between vertical and the seat stay tends to be larger than that between vertical and front fork, the seat stay already would need to be a bit fatter (the fork is relatively more compressed and relatively less bent than the seat stay)

Also, the force you exert on the chain when riding the bike tries to bend the seat stay, too. That, too, would require a stronger seat stay.

However, there is a better (in the sense that it makes the frame stronger at the same weight or gives you a lighter frame of the same strength): the chain stay. It introduces a triangle in the structure, and triangles are strong.

it's missing the rods connecting the rear axle with the pedal's axle..

The frame is missing the tube between the rear wheel hub and where the pedals connect - it would presumably splay out if you sat on it.

If you're really lucky, then the chain would provide some strength. Pedaling would be really hard with such a tight chain, though.

...and anyway, the frame would flex a lot, likely dropping the chain.

Just to expand on what others said, the tubes that the frame is missing are called chainstays.

Is it really impossible to build such a bike? Given a strong enough material it would be possible. I have not idea about the structural analysis in this case. Does such a material exist?

I can't see what the advantage would be though - if you do have a wonder material better to go with a more standard frame design and increase stiffness and/or reduce weight.

NB ~20 years ago I did have an "elevated stay" frame which was neat in some ways - no chain slap and the chain didn't go through the frame. However, the frame failed catastrophically while I was at traffic lights....

"I have not idea about the structural analysis in this case."

There's your problem. The chainstays are there for Good Reasons. http://www.mece.ualberta.ca/tutorials/ansys/BT/Bike/Bike.htm... If you take them out, now most forces on the bike effect one point in the frame, right beneath the saddle. Making the frame stronger requires more material (=weight) or better material (=price), whereas a rhombus of two triangles solves the problem efficiently.

In other words, you are proposing a problem to which the current bike design is the solution.

Likely not impossible, but the crucial weak point would probably be the connection with the seat tube. Independent of the material, that place would need some heavy gusseting/reinforcement. That particular bike also has a very vulnerable connection to the head tube, as only the down tube connects to it.

There are bikes without a rear triangle, but they (almost?) always lack the seatstay instead of the chainstay or have what could be considered something in between a chainstay/seatstay. Here are some examples:

http://i.imgur.com/F1xkdc1.jpg

http://i.imgur.com/oTFbEy7.jpg

http://i.imgur.com/XxRNe5y.jpg

In practice, bikes that diverge from 2 triangles eschew the support between the rear hub and the seat:

https://www.google.com/search?q=carbon+fiber+bike+frame

(the results are mostly traditional, there are some with a different configuration for the frame supporting the rear hub)

Here are some labelled pictures to help everyone with the terminology when discussing various missing bits of the frame:

http://www.pinkbike.com/photo/2899038/

http://www.eandsweb.com/trails/info/bike_buy.html

Great little project. Some of them clearly wouldn't work but some would be fun to try and make

I was looking on my phone and didn't actually see the one by the doctor. Was it there?

I would say 8th one on the right. it could pass as his handwriting or a bike

There are 4 of them. 3rd, 10th on the right, 11th on the left and 3rd to last on the right. It's "medico" in Italian, it could be "dottore" but it's a more general term.

I think it's the 10th on the right.

I was so disappointed when I realized these images were not real! Awesome project.

I'm curious, why does he call them "men's bicycle"?

A "men's bicycle" is a bike with a diamond frame (as opposed to step-through for a woman's bicycle), but it's a silly name really. More to do with comfort vs. performance than gender.

> More to do with comfort vs. performance than gender.

Could you expand on that? Which bikes are on the comfort side and which ones on the performance side of the tradeoff?

A diamond frame is stiffer and lighter, but you can only mount it by swinging your leg over the saddle or over the handlebars. A step-through frame is heavier but easier to mount.

Because there are also "female's bicycles".

Historically these bikes were designed for women. See the top two answers here:

http://bicycles.stackexchange.com/questions/13826/what-are-t...

Because women may need to ride a bike in a skirt or dress (less commonly now, but the tradition persists), so they had bikes with an extremely low top tube to step through.

I think because in Italy the different models are called "man bicycle" and "woman bycicle" ("bici da uomo" and "bici da donna", respectively). How are they called in English?

Men's bicycle and women's bicycle in the UK.

Disappointed this isn't about velociraptors :(

Brooks saddles are a nice touch :)

A similar challenge: draw an ant.

What software does he use?

Photoshop, probably. These are image montages, not 3D renders.

Reply on news.ycombinator.com