A Cuban man trying to build the world's tallest bike | Hacker News Reader

A Cuban man trying to build the world's tallest bike

bbc.com

85 pointshwayern69 comments

To put that into perspective, here's a cool video of a guy riding through LA on a 14.5' (4.4m) bike. https://vimeo.com/64653759

This is my go-to tall bike video too. What's especially great is the way he dismounts :-)

AND it's a fixie?? Is that the norm for tall-bikes? We have a bunch here in Portland (Ore.) and I always figured they had breaks but never really looked closely... but I see none in the video. That seems 10x as terrifying.

No, it's a coaster brake single speed. Back pressure on the chain engages the hub brake. You can see him coast at 2:20.

A fixie for a tall bike makes sense because one can (presumably?) track stand to keep the bike upright while stopped. Otherwise you gotta hope there's a stop sign you can lean up against or just never stop...

Well, his technique of having a crowd of cops and fellow riders to block traffic for you seems to work for getting around without having to stop. Maybe not practical for everyday riding, though...

I'm amazed it works as it is, he's going pretty slow at times. All it takes is one person not noticing and it's done.

It's a long fall - if vertical that's about 1.7s and if he falls in an arc it would be longer. It could easily kill the person that gets hit too.

Usually what you do is keep moving and either turn right with traffic or circle around. You can also grab onto something but if you're on the street there isn't really anything within reach. A track stand is hard to pull off for very long for even experienced riders on normal fixies.

I've seen only one fixie tallbike. It's a hard thing to pull off because even at very high chain tension, a run of chain that long has a lot of slop.

This one is singlespeed (you can see him coast a few times), and I am not even sure it has a brake at all! I didn't see a coaster brake arm at the end of the video where the drivetrain is visible. (EDIT: I am wrong, there is a coaster brake.)

@gemache is right, they're mostly single speed. It's way too easy to have the chain slip off, and when that happens you have no choice but to bail. That happened to me before and I broke my foot.

I had one and rode it for years. Single speed, no brakes. I stopped by putting my foot down on the rear tire :)

That's very impressive, especially the balance so high up. If you'd overbalance even a little bit there is absolutely no stopping it until you hit the ground.

The creator/rider of that bike recently went to Cuba with a suitcase full of bike part parts to help out.

This is madness. I recently fell off the second rung of a ladder onto concrete (shoe got caught), and even that hurt, third or fourth rung might have been a broken arm.

Falling from this thing is guaranteed serious injury or even death. It would be very easy to add some kind of simple automatic kickstand in case of tipping over laterally.

It's demonstrably not the madness you suggest it is, he's been doing it for decades and he's still in one piece. You see alternative sports athletes walking away from death defying stunts gone awry on a regular basis. Wiping out is a learned skill, and an under-appreciated one. A rough and tumble youth will save you from needing hip replacement surgery when you slip on an icy step when you're 80.

Bikes are even worse generally because you fall laterally and we don't have the neck muscles to stop the head hitting concrete. When you fall off a normal bike it's not normally the speed that determines the head injury.

Does anyone know what the rules are for breaking this record? If I attached a small hot air balloon to the top of the bike, I could conceivably make a ridiculously tall bike that's safe to operate. In fact, to keep within the rules, I could keep the balloon at equilibrium most of the time (so it doesn't lift the bike at all) until an emergency. Would the balloon invalidate my attempt to break the record?

Would you want to break the record like that? No one would respect you or the record. Sometimes these things come down to how you want to feel about yourself.

The records are by the distance from ground to the top of the seat where the rider sits.

This would preclude the balloon trick. :)

Not really, the balloon would be attached to the top of the bike at let's say 15 meters high and would itself go maybe another 5 or 10 meters up trailing the wire to the bike.

So the rider would still be at the right distance from the ground, it's just that the bike can't fall over anymore because the balloon will help to catch it. You could sit still all day long on that thing (or until the wind caught the balloon...).

The downside of the scheme is the negative feedback loop in the bike once it did became unbalanced. When it's almost balanced it would not take much upwards force to keep it that way but once it starts to become unbalanced the force required will very quickly overpower the balloon.

Or you'd have to make the balloon so large that it would be just incapable of lifting bike + rider off the ground.

The balloon isn't necessary. Inverted pendulums become more stable the taller they get. Think of trying to balance a short pencil on your palm (difficult) versus balancing a broomstick (much easier). Tall bicycles are inherently very stable, and don't need any help with balancing. The difficulty is in climbing that high up to the seat.

Would be nice to have in case of an unexpected stop though...

I don't think it would be. It'd have to have an upwards buoyant force of most of your body weight to really be effective. At that point we are talking about a huge balloon, meaning it'll cause a lot of air resistance which will cause problems when you're attempting to ride. You'll also lose a lot of traction. I think in the end it'd make it easier to be tipped over (especially if it catches a wind gust), and so would be self-defeating.

OK, so.. a pressurized helium tank that could be blown into a balloon in an emergency like a submarine ballast tank...

Ugh. I had a bit of an unfortunate accident last summer with a recumbent and just looking at this hurts, that's a very bad height to fall from, I had plenty of damage being 8" off the ground.

My thoughts exactly -- I fell off an ordinary bicycle at moderate speed last year, and suffered three cracked ribs and a concussion as a result. This fellow is courting disaster!

Tall bikes are intentionally absurd but so fun to ride, it's hard not to smile from ear to ear while rolling down the road perched high above the world.

https://www.youtube.com/watch?v=v-XS4aueDUg

How Cuba DIY's its existence Quite bunch of interesting hackers

Here in Asheville, NC we had a fellow who built and attempted to ride a 44 ft. (13.4m) tall bike at a festival. He did not ride far enough to make it in the record books. But it was exciting. https://www.youtube.com/watch?v=-WgBeW4LXcU

Hah, splendid! One of my favourite Makers on youtube, Laura Kampf from Köln, also built her own "tallbike". It's smaller than Cepero's, but there's a video of her actually building it:

https://www.youtube.com/watch?v=XWZnGQiSbtQ

> After more than half a century of living under a trade embargo, many Cubans have grown accustomed to shortages of basic household goods

Are there countries other than the U.S. with an embargo against Cuba? What's stopping them from trading with China or Mexico or Canada or the E.U. countries for basic household goods?

They aren't a rich country, and so don't have a lot of money to buy imports with. Not having access to the main large nearby trading partner doesn't help.

This is innecessarily dangerous. It only would take a stroke of wind or an accidental kick to kill the biker. If this guy accept some ideas; such bike should be designed as a tumbler doll and add a seat belt for the biker. If you can mechanically raise the heavy piece to balance (lower) the upper part could even have a supercool mechanism to dismount or save low obstacles.

We must seem like ants to them.

Archive.is copy for those of us inside the UK:

http://archive.is/EXWhb

I vote for less rectangles and more triangles (like the smaller bike in the picture). It is more structurally sound that way.

Maybe someone who knows more about structures can comment, but I guess the big issue is how rigid the joints are. A triangulated structure is good because the joints don't need to be fixed--they can be hinged pin-joints and the frame is still rigid + easier to calculate structurally. But if the joints are very rigid, you can go with slightly less efficient option of rectangular framing if that's more convenient.

In architecture it's sometimes called a Vierendeel truss, https://en.wikipedia.org/wiki/Vierendeel_bridge and it's very handy for avoiding inconvenient diagonal columns. (There are some high-profile buildings that use it, e.g. the Salk Institute in La Jolla, the HSBC building in Hong Kong.)

A triangle structure is significantly more rigid than a rectangular one. Vierendeel truss needs to be super rigid to resist flex. Not good for a bicycle.

how one gets on top of it, how to stop on the light, how to hop off?

Getting up and down? With something this tall, it's a rolling ladder, you stop against a building, or have someone supporting your stop.

Stopping at a light? Ideally you don't, you time the light, ride in circles, or hope oncoming traffic stops for you. I wouldn't recommend the latter.

I've seen riders with cleats who can stop without putting their feet down. This is even without a fixed gear.

I think you're talking about a track stand.

https://en.wikipedia.org/wiki/Track_stand

A common skill for expert cyclists, but maybe not a good idea to rely on if you're going to fall 4 meters or more to the ground if you lose control of the track stand.

Not to mention it'd be a lot tougher from that high up in the first place. I can do that on a mountain bike pretty easily for a minute or so, but at broken-bone height? No way.

Why do you say it'd be tougher from that high up? I suspect it'd be easier. Inverse pendulums are more stable the longer they are.

what happen if he falls?

Hopefully he lands on his feet.

At 10 meters you're likely to break something even if you land on your feet.

If you know how to fall it isn't impossible to avoid injury from 10m. You're right at the limit of where you need to be really fit and avoid doing it too many times though. There is the added complication of needing to fall away from the bike as well, landing on it would be very bad news.

That's really rolling the dice. 10m is (more than) enough for a fatality, if you get away without injury you're just lucky, especially trying to dis-entangle yourself from a falling bicycle.

As the bike starts to topple, I wonder if you could climb down it quickly enough to avoid jumping.

Kinda like this https://www.youtube.com/watch?v=vvOKyFmiUFA

That ladder is supported on both ends. Just to reach over while it is falling requires you to shift to the side it is falling away from accelerating the fall even further.

It would be like being astride that ladder rather than clinging to the side of it and then going over the top and then sliding down on the side furthest from the ground.

Not something I'd like to try.

My reference would be the 10m diving platform at my local pool. Looking down, it was terrifying enough jumping into water from there.

Naively, v = sqrt(2gh), so you'd be hitting the concrete at ~50kph (30mph). Though, perhaps you could somehow use the bike to lessen your fall.

> Though, perhaps you could somehow use the bike to lessen your fall.

Or you might get it to give you a nice little kick after you've already landed yourself.

At least that limits the damage to the bike ;)

> 50kph

That's a lot of speed for, basically, running straight into a brick wall.

Better to break your legs than your skull.

Hospital with a couple of broken bones if he's lucky.

That's the thing about tall bikes: The only rule is don't fall. Fortunately they're inherently very stable, but if the bottom of the bicycle gets knocked from beneath you by a car or something, it's bad news.

"We're sorry but this site is not accessible from the UK as it is part of our international service and is not funded by the licence fee. It is run commercially by BBC Worldwide, a wholly-owned subsidiary of the BBC, the profits made from it go back to BBC programme-makers to help fund great new BBC programmes. You can find out more about BBC Worldwide and its digital activities at www.bbcworldwide.com."

British Broadcasting Service branded site is unavailable in the UK. Weird.

You just saved yourself 2.5MB of bandwidth and a 10 second page load.

Is anyone talking about changing the funding model of the BBC though? It doesn't seem cut out for the online world.

My british vpn gives me free BBC.... I'd say it's pretty sweet!

You well illustrated his point.

They do bring it up every so often, but any politician that is interviewed about it is generally interviewed on the BBC. Also, the public love the BBC and don't mind paying.

The BBC is really good online for us in the UK. I know a few people who work there and they are using cutting edge tech on a shoe string budget. They really do a brilliant job.

Personally I don't mind paying for the Beeb and some other people in the world get it for free.

Wow, I thought I was the only one!

I don't get the anti-license fee brigade. If you don't want to pay just don't watch the BBC TV channels. The BBC won't even stop you reading their websites and listening to their radio stations commercial-free if you don't pay. Seems like a good deal to me.

That is the problem, as more people shift to online independent media could dissapear.

> If you don't want to pay just don't watch the BBC TV channels.

You need a license to watch other broadcast channels like ITV C4 (not on catchup though) etc. I don't have one because I don't like the BBC's politics editorial positions.

Here's another news story about the same man: http://www.miamiherald.com/news/nation-world/world/americas/...

Weird that we have to go to Miami to get our news, but oh well.

I will pay the bbc tax only if I can read articles from bbc in the UK. (I'm not watching live TV though at all)

This isn't an article by the BBC "proper", it's by a separate organisation which is owned by the BBC, but is solely funded by the BBC's overseas operations.

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