[HN Gopher] 134.5 kg Concrete Bike [video]
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134.5 kg Concrete Bike [video]
Author : zdw
Score : 184 points
Date : 2022-08-31 16:44 UTC (6 hours ago)
(HTM) web link (www.youtube.com)
(TXT) w3m dump (www.youtube.com)
| aortega wrote:
| Bikes are incredibly simple devices, it's amazing that they were
| not invented up until 200 years ago.
| 323 wrote:
| The chain requires some pretty fine engineering. Arguably
| jewelry makers had it.
| tromp wrote:
| 205 years to be precise: https://www.bricsys.com/en-
| eu/blog/the-first-bicycles
| soperj wrote:
| Rubber. It's a product of the Americas, before that, wheels
| sucked.
| kccqzy wrote:
| No they are not. Most people can't explain off the top of their
| head how the derailleur works to move the chain from one cog to
| another, or how freewheeling allows the wheel to move without
| the pedals to move, or even how the cable allows brakes to be
| remotely activated from the handlebar. Most people can't even
| explain why it is possible for a bike to be stable while moving
| but can't stand on its own. It's counter-intuitive.
|
| There's plenty of ingenuity in the design of a modern bike.
| xdennis wrote:
| Most of what you're describing isn't necessary for a bike. A
| fixie bike doesn't have a derailleur or freewheeling. And you
| can slow down without breaks.
|
| You can even remove the chain. A penny-farthing bike is a
| surprisingly simple device. It is surprising it wasn't
| invented earlier.
|
| My guess would be that they weren't invented earlier because
| they are not that useful without good roads.
| nullc wrote:
| the steering geometry of a modern bike is not entirely obvious,
| most configurations are either unstable or unsteerable. Plus a
| bike is unusable if you don't know how to ride it, so even if
| you stumbled on a stable steering configuration you might give
| up on it before you learned to ride it.
| frostwarrior wrote:
| Imagine getting hit by a car.
|
| Poor car.
| topspin wrote:
| That's the thought I had; at least the car would take some
| damage.
| kube-system wrote:
| It's similar weight to a small motorcycle.
| ginko wrote:
| The main thing it seems to be missing is brakes.
| tokai wrote:
| Its fixed gear. Your brake is to stop pedaling.
| Lukas_Skywalker wrote:
| I thought so too, but at 20:55 you can see the rider stop
| pedalling while still rolling. It seems to contain a
| freewheel mechanism: https://youtu.be/Yqgn-qlg1X0?t=1255
| pier25 wrote:
| Yeah. Good luck stopping that thing with a bit of speed. Notice
| that in the video he always pedals super slowly.
| barbazoo wrote:
| At https://youtu.be/Yqgn-qlg1X0?t=312 I wondered why the back
| dropout* was facing upwards but then later at
| https://youtu.be/Yqgn-qlg1X0?t=1109 they seemed to have fixed it?
|
| * the part of the frame that attaches to the wheel
| dvirsky wrote:
| I was wondering that too, thought I missed something.
| Lukas_Skywalker wrote:
| The frame is upside down. You can see the bottom bracket is
| on top, and the seat tube is facing down.
| barbazoo wrote:
| oh yes you're right!!!
| tromp wrote:
| My favorite part of this project has got to be the helmet. For
| one, because it's pure concrete, with no metal frame inside it
| like the other parts. And second, because it best illustrates the
| utility of the project in that a concrete helmet is literally
| worse than useless.
| jfim wrote:
| Reminds me of those yearly engineering competitions where
| students build canoes out of concrete and race them:
| https://en.m.wikipedia.org/wiki/Concrete_canoe
| acomjean wrote:
| Ah my Civil Engineering student years.. Except my year, because
| the year before the canoe wasn't right, and the sponsoring
| professor swamped the thing and took a year off (or so was the
| rumor), so our class never got to build one.
| morepork wrote:
| Now don't take this near any hills
| kogus wrote:
| This reminds me of my own wacky idea for a line of fitness
| products: ordinary everyday items that are normal in every way
| except that they are intentionally designed to be physically
| challenging to use.
|
| For example, doors that require a lot of force to open, keyboards
| with 1lb resistance springs, remote controls that weigh several
| kilograms, etc. Since many people have trouble going to the gym,
| it would be a way to introduce weight training in a way that was
| both unobtrusive and unavoidable.
|
| Just one of those things that has been bouncing around in my head
| for years now. I think riding this bike would definitely qualify
| as weight training :)
| egman_ekki wrote:
| https://youtu.be/FCvtqy4-RS8
| klyrs wrote:
| I once met a guy on a bike ride who trained with a kids trailer
| loaded down with bricks. He claimed that it was more time-
| efficient way to train, and on race days, his bike felt like it
| was made of helium. My only concerns are wear&tear on knees,
| and the risk of a crash, getting smashed by a 200lb trailer
| doesn't sound fun.
| nradov wrote:
| The Airhub resistance trainer is a safer option. It can
| selectively apply magnetic resistance (drag) in order to make
| training rides harder. But when switched off the bike rides
| like normal, and there are no extra safety risks.
|
| https://airhub.com.au/
|
| Wear on the knees is more an issue of proper bike fit and
| pedaling technique. If you want to get fit as a cyclist then
| you have to put in some high wattage training rides. Whether
| the resistance comes from a heavy trailer or a steep hill or
| whatever makes no difference to the knee injury risk.
| squarefoot wrote:
| It's much easier to get married, so you'll have the weekly task
| of going to the store by foot and bring back bagfuls of
| groceries, and possibly two packs of bottled water... then
| return there because you forgot two bags of cat's litter:)
|
| More seriously, ages ago I wondered about a way to generate
| power by making sort of a (very compact) exoskeleton-like
| contraption for each limb articulation, so walking or using
| arms would activate some generators. Mechanical construction
| would be quite a challenge, however if built in a very compact
| wearable way it could become a thing: sensors for body
| parameters could self power, the phone in a pocket equipped
| with a inductive charger would charge while running, etc.
| hetspookjee wrote:
| For some reason the feeling of getting exhausted on an
| ultralight racing bike feels much easier on the mind than
| getting exhausted on a regular bike with a flat tire. Similar
| with swimming with slick gear versus swimming with long shorts
| and a shirt.
| jjcm wrote:
| There's something to be said about overloading the effort
| required though. We used to train endurance by dragging a
| tire behind us in the water. When it came to race day,
| everything would feel 10x easier.
| avrionov wrote:
| SNL did a sketch about it:
| https://www.youtube.com/watch?v=vZRzJJcq6Rs
| trhway wrote:
| Famous Russian wrestler a century ago walked with a cane 16 kg
| weight.
|
| For simple mortals like me - while hiking I've been using the
| Nordic poles with 8 inches springed amortization which
| naturally works up your upper body.
| asasidh wrote:
| they call it functional training
| agumonkey wrote:
| It would be a cosmic irony, since humans have been trying to
| make things "easier" since at least 4000 years.
|
| I have another idea, make a lot of crank generators so that
| biochemical energy gets converted into electricity. I know you
| won't power your kettle nor your telsa but considering people
| 1) pay for exercise [0] 2) pay to power the devices to exercise
| .. I think it's due time.
|
| [0] gym club managed to market gravity (and social context, but
| mostly gravity).
| jamal-kumar wrote:
| Kind of the extremely radical opposite to the reasoning behind
| accessibility, then? Ever have someone in a wheelchair get mad
| at you?
| na85 wrote:
| Good luck catching me on their intentionally-hard-to-push
| chair.
|
| Think of the profits from thiw move fast and break things
| approach! Always be hustling.
| nicbou wrote:
| Move slow and get ripped
| LoveMortuus wrote:
| What about just wearing a weighted vest?
|
| Another interesting idea I've had many many years ago: Skies
| that have enough buoyancy to be able to float on the sea while
| a person is standing on them. Do that you ski across the sea.
| Although the movement would be closer to rollerblades, due to
| lack of hills.
| marcodiego wrote:
| > keyboards with 1lb resistance springs
|
| This may be a good recipe for tendinitis.
| tinalumfoil wrote:
| Everything here sounds like a recipe for injury. When you're
| lifting heavy things you should be focused on (correctly)
| lifting the heavy thing. If you turn the oven door into a
| deadlift you're going to forget one day and throw out your
| back.
| xeromal wrote:
| nicbou wrote:
| Have you heard of crossfit?
| Swenrekcah wrote:
| After three days of the 4kg remote you'll be over at your
| date's house and promptly punch her in the face when
| picking up her remote.
| mabbo wrote:
| You're thinking too small, friend.
|
| Build a space station with gravity via rotation. Then spin it
| up to 150% of normal gravity. Now everything is 50% heavier,
| yourself included!
| animatedb wrote:
| You are thinking much too small, friend. Spin the earth
| faster and we can finally get rid of leap seconds.
| squarefoot wrote:
| That would defeat the initial purpose as faster Earth
| rotation would also make us lighter.
| littlestymaar wrote:
| Strong Goku vibe.
| nicbou wrote:
| I wish that VC wasted money on you instead of the same boring
| mobility startups.
| dcminter wrote:
| You don't even need to be in space if you want to make things
| heavier. As always the great David Jones (Daedalus) had this
| idea first in his New Scientist column (16th Feb 1968), and
| it's included in the compendium "The inventions of Daedalus"
| Retric wrote:
| The idea is much older for example 1948:
| https://en.wikipedia.org/wiki/Rotor_(ride)
|
| Various test chambers for astronauts where built to test
| how people respond to higher gravity / a rotating reference
| frame. Actually trying to do this runs into some unexpected
| issues in practice. Here is a Tom Scott video about a more
| recent example: https://youtu.be/bJ_seXo-Enc
| andai wrote:
| Is this available to read online? Alternatively, could you
| summarize the idea?
| skocznymroczny wrote:
| > keyboards with 1lb resistance springs
|
| I'm sure there would be mech keyboard enthusiasts who would
| find the actuation force too light on those
| 323 wrote:
| > _remote controls that weigh several kilograms_
|
| That would require either very expensive metals, or a giant
| remote control.
|
| But something like this is already done - a lot of people use
| leg weights as an extra in the gym.
| jffry wrote:
| 1kg of lead is like 90mL. I just measured my quite svelte TV
| remote at 22cm x 2cm x 5cm = 220mL. I'm sure you could easily
| fit 1.5 kilos of lead in there, and with a slightly thicker
| "A/V receiver" style remote we could easily make that 3-4kg
| throwaway0a5e wrote:
| Unfortunately the venn diagram between "people who want a
| heavy remote for physical fitness reasons" and "people who
| will absolutely lose their minds when they find out it has
| lead in it no matter how safely you have encapsulated it"
| is pretty close to a circle.
| jffry wrote:
| That's OK, the lead remote is simply an anchor pricing
| option (heh), we can sell those people a luxury tungsten
| weighted remote instead!
|
| As an added bonus we can pack in 70% more mass in the
| same space
| samatman wrote:
| The door idea is a safety issue, but there's a market for a
| gag-gift remote control holder that's a barbell, for sure.
| Whether it helps anyone is an open question, but it hits the
| sweet spot for twee Americana gas station stuff.
| adrianmonk wrote:
| This is similar to my business plan where I start a combo
| moving company / personal training service and charge people to
| move other people's furniture. Double profit!
| ihaveajob wrote:
| It reminds me of "u-pick" farms. Less labor, higher prices.
| The only constraint is that they have to be somewhere easy to
| reach.
| tomjakubowski wrote:
| Jack Garbarino beat you to it. Read The Movement; there's a
| copy on my shelf.
| phito wrote:
| https://www.youtube.com/watch?v=LkNxvUrWQ_Q :)
| shepherdjerred wrote:
| I watched this episode just last night. Incredible
|
| He's got a new show out:
| https://www.imdb.com/title/tt10802170/
| adrianmonk wrote:
| Hah, so I guess I'm not the only one with that idea then.
| acomjean wrote:
| Its not quite the same but one of the Moving Companies around
| boston has a rowing club.
|
| https://www.gentlegiantrowing.org/sponsor
|
| "and approach to moving as a sport, requiring dedication and
| teamwork. Many Gentle Giant employees are current or former
| athletes from a wide variety of sports and competitive
| backgrounds. Current and former employees include both
| Olympic, collegiate and club rowers."
| caboteria wrote:
| Gentle Giant is really more of a rowing club that has a
| moving company. They moved our company a few years back and
| I've never seen anyone carry as much weight as quickly and
| effortlessly as those guys.
| sandworm101 wrote:
| Except that moving boxes and furniture doesnt promote
| fitness. Most of your time will be sitting in a truck. Then
| it will be repetitive motions with moderate weights. It would
| be more akin to life as a fedex driver than a modern workout.
| fredley wrote:
| Have you heard of Good Gym in the UK?
|
| https://www.goodgym.org/
| xeromal wrote:
| What a fun idea!
| trhway wrote:
| Such scheme is somewhat popular in agriculture where city
| dwellers come to work on a farm and are paying for the
| experience.
| squidgyhead wrote:
| I have the same plan! We can team up!
| Swenrekcah wrote:
| We think alike! I would have started that company years ago
| if not for the threat of the inevitable lawsuit when a client
| drops a grand piano on someone's head.
| agumonkey wrote:
| Holy .. I wanted to do just that.
| IshKebab wrote:
| I've definitely seen deliveroo cyclists doing it for the
| fitness.
| xuhu wrote:
| And the reason it's easier to make than a wooden bike is that you
| can take a normal bike and pour concrete onto each element.
| kfnic wrote:
| William Osman on YouTube made a bike fully out of wood:
| https://www.youtube.com/watch?v=0yJdz-kjfLk
|
| [haven't finished the video yet, not sure if this or something
| similar was mentioned]
| kawsper wrote:
| Someone in the UK made a wooden frame:
| https://youtu.be/jd0vt5v37B0
| [deleted]
| kosyblysk666 wrote:
| sgjohnson wrote:
| I wonder if they could make one from Iridium now. Now that would
| be flashy.
| matthewfcarlson wrote:
| If nothing else, it's a good way to get in shape
| system2 wrote:
| Or break some limbs.
| stavros wrote:
| If that shape is flat...
| [deleted]
| tomcam wrote:
| I have seen plenty of bikes that could pass as sculptures but
| this is the first sculpture I've seen that could be used as a
| bike.
| c2h5oh wrote:
| I strongly suspect that the steel reinforcement used in the frame
| could have acted as a rigid enough frame without the concrete
| amelius wrote:
| I strongly suspect they could just as well have used a normal
| bike and cast the concrete around it (which they did for some
| parts) ...
| wolpoli wrote:
| I suspect that the concrete will crack if it is just molded
| to the frame itself. Concrete cracks easily without support.
| epakai wrote:
| It sort of does. You can see the fork got damaged mid-span in
| some of the riding shots. Still there isn't enough strength in
| places like the fork ends or crown without the concrete.
| [deleted]
| [deleted]
| ejb999 wrote:
| correct, it is a steel framed bike, covered with concrete - not
| a concrete bike.
| m1117 wrote:
| This is also how google approaches product design
| djmips wrote:
| This is a metaphor for poorly designed software. Don't worry
| we'll optimize it at the end!
| amenghra wrote:
| Sounds like a bulldozer. Love it!
| Theodores wrote:
| I have always wanted to make a mountain bike out of scaffolding
| poles in order to review it positively.
|
| Notionally such a bike should score highly in many key metrics.
| In the review the obvious failings are overlooked yet the reader
| can work it out for themselves.
| bch wrote:
| I remember in the 1980s _Bicycling_ or some such magazine wrapped
| a road bike in concrete, called it a composite bicycle and did a
| full review. Needless to say, it scored poorly.
| peteradio wrote:
| I'm glad they included springs on the seat, otherwise that could
| have been an uncomfortable ride.
| lizardactivist wrote:
| Only ex-bodybuilders turned bike thiefs would think of stealing
| that!
| ChrisMarshallNY wrote:
| So now bicyclists can suffer the same class of life-threatening
| injury that motorcyclists do!
| cryptodan wrote:
| The DeLorean went to far back.
| korse wrote:
| Not a whole lot of engineers on here I guess?
|
| https://en.wikipedia.org/wiki/Great_Northern_Concrete_Tobogg...
| mkoryak wrote:
| when I lived in JP (a part of Boston) I made my commuter bike
| "unstealable" by taping it and putting joint compound all over
| the frame. The thing was ugly as sin and looked at lot like this
| bike.
|
| I could leave it locked with one of those cheap combination cable
| locks, and no one ever took it.
| krasin wrote:
| Do you happen to have photos of the bike?
| elicash wrote:
| I like this. But alternatively, couldn't that make it look
| abandoned and possibly have the opposite effect?
| blamazon wrote:
| I do this with extension cords, bit of electrical tape and most
| potential yoinkers will think twice about yoinking.
| djmips wrote:
| I do this to my own body - bits of electrical tape - I am
| virtually un-kidnap-able now.
| derac wrote:
| The level of maker youtube projects has been going off the
| charts.
|
| Some examples from less well-known creators:
|
| Drunk Mel Gibson arrest diorama https://youtu.be/2UoHb0ziMDA
|
| Knife throwing machine https://youtu.be/-BKEZbYOMpI
|
| 3d printed harmonic drive https://youtu.be/Emvo3bLT-Z4
| donjoe wrote:
| The knife throwing machine reminds me a lot of the slingshot
| channel:
|
| https://youtube.com/c/Slingshotchannel
| causi wrote:
| Rather misleading since the concrete isn't even structurally
| integral to the bike. It's more like a rebar bike that had
| concrete poured on it.
| ddkto wrote:
| I suppose the technically correct term would be reinforced
| concrete bike
| cptskippy wrote:
| I would say "I covered a bike in concrete" would be the most
| accurate title.
| stingrae wrote:
| to be fair, large amounts of the frame are not just merely
| covered in concrete
| cptskippy wrote:
| Yes, and the entire thing is either reinforced with rebar
| or structurally dependent on actual bicycle parts. You
| could argue that the rebar reinforcements, if welded
| together, would make a sufficient frame and the concrete
| is primarily acting as a bonding agent.
| gpt5 wrote:
| It seems like they could achieve the same results by pouring
| concrete around a real bike frame (instead of build a bike
| frame out of rebar).
| Kaibeezy wrote:
| The combination with steel is what gives concrete its power.
| It's a composite material created by the two things together.
| Concrete surrounds the steel frame and penetrates it. It
| binds the steel together.
| version_five wrote:
| The same thought went through my mind watching it, but you
| could say the same about most (many?) concrete structures.
| Someone with a structural background could explain better, but
| I believe the rebar and concrete provide different kinds of
| strength, like concrete is compressive strong (and keeps the
| minimal amount of rebar from moving around and bending, while
| the rebar keeps the concrete from cracking. Even for the bike,
| it wouldn't be the same structurally if they just wired up a
| rebar frame
| pkaye wrote:
| I took civil engineering a long ago in college but diverged
| on my career. This is what I recall.
|
| In reinforce concrete beams the bending causes compression on
| the top and tension on the bottom. Since concrete is weak in
| tension (maybe 1/10 of compression strength), the rebar at
| the bottom will carry the tension. When you do the design
| calculations, some approximations are made like concrete
| carries no tension on bottom half of beam and how the stress
| is distributed on the top portion. Then with iterative
| analysis you can converge on an solution. Then once you got
| the basic design, there will other rules like displacement,
| buckling conditions.
|
| Here is an example design calculation I could find:
| https://civilengineeringbible.com/subtopics.php?i=32
| pwg wrote:
| > but I believe the rebar and concrete provide different
| kinds of strength
|
| Yes, concrete provides great compressive strength, but is not
| very strong given tensile loading.
|
| Rebar provides the tensile loading support that concrete
| alone lacks.
|
| See: https://en.wikipedia.org/wiki/Rebar
| TheDudeMan wrote:
| Yes, but it doesn't matter for a bike. Riding it is not going
| to crumple that amount of rebar.
| stergios wrote:
| The front left fork failed. You can see the crack in the
| video as he is riding. The front fork has a bending moment
| as well as compressive force. When the bending force was
| applied the concrete failed and the rebar did not.
|
| Overall, I really liked this as an art project. I'm not
| sure what the artist wants to communicate with the bike,
| but I found it very satisfying.
| JKCalhoun wrote:
| I'd like to think they're reminding us why we don't make
| bikes out of concrete (but we can!).
| debacle wrote:
| > I'm not sure what the artist wants to communicate with
| the bike
|
| "I paid a lot of money for an architecture degree I'm not
| using."
| 2muchcoffeeman wrote:
| How much of this can you just chalk up to using concrete
| and just copying the design of a normal bike? This is a
| fun art project but doesn't seem like much more.
|
| Sorry for being negative about an art project. I think I
| was projecting my own biases, but it sounded like an
| engineering project and then I didn't learn anything.
| prvc wrote:
| Yes, but why? And isn't it more of a bike covered in concrete
| than a concrete bike?
| z9znz wrote:
| Oh there's a lot of fun concepts to muse about. But one is
| brakes.
|
| That aside, at least it wouldn't get stolen in Amsterdam.
|
| Which reminds me of something a friend did. He lived in a
| neighborhood where anything visible would be stolen. So he took
| an old computer tower case and filled it with concrete. Then he
| left it on his front porch.
|
| Predictably some guy tried to steal it. The poor fool managed to
| move it one house over before giving up and dropping it in the
| street.
| hooverd wrote:
| Finally, the secret to how those bike-share bikes are made.
| utopcell wrote:
| It's great that he added concrete steps for creating the bike.
| bjourne wrote:
| That's brutal.
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(page generated 2022-08-31 23:00 UTC)