Spring-powered wheel claims to be ‘E-bike alternative at lower cost’ | Hacker News Reader

Spring-powered wheel claims to be ‘E-bike alternative at lower cost’

cyclingweekly.com

43 pointsJaruzel76 comments

This article has all the makings of a perpetual motion machine. Those are normally found by using either "springs", "magnets" or a combination of both.

There is theoretically a way to use the roughness of the terrain (so the bike going up and down as it rides) to store that energy and then use that for propulsion. When finding a rough spot, the bike trades forward momentum for a vertical impulse, so it might be possible to transform a part of this back to horizontal. I don't have a basis to calculate this, but my intuition tells me accounting for loses this energy must be very small and very difficult to capture, to the point of almost worthless. Think of a wave energy generator, but on a calm day with waves almost flat.

The article doesn't claim that though ("10kg active weight [...] generate a moment ranging from 7.3Nm to 7.8Nm"), so this is either bad reporting or a perpetual motion scam. My money is on the latter specially seeing the "infinite power assistance" label on the video, would be happy to be proven wrong though!

Fun fact: In 1775 the Royal Academy of Sciences in Paris stopped accepting proposals concerning perpetual motion.

I concur, and this smells of bullshit. Unfortunately they don't show inside their magic box, so I can't see whats happening on the inside. I did notice that the springs were completely missing on one of their demos in the video though!

There is some research into how much energy is lost to suspension style losses, and it's on the order of 100W (was 300) when riding at 20mph/30kph over rumble strips. (https://www.renehersecycles.com/myth-17-bigger-wheels-roll-f...). This can be changed pretty dramatically with good tires and proper inflation.

On more reasonable road surfaces, it's less than 1/10th of that number. (but good tires make ooooh so much of a difference. I don't notice bad chipseal. My clubmates -- not so much)

(edit sorry -- rereading the article, I misread the graph. 300W on the rumble strips ~200 on the smooth pavement beside them)

Thanks for linking the article! It seems to say that 300W is the energy needed on the rough terrain, not the energy consumed by the bumps: "We measured the power required to pedal the bike at 32.2 km/h (20 mph) using an SRM crank."

Then it goes on to measure the energy required on the smooth pavement and it's around 230W. So around 70W of INPUT energy is needed because of the strips.

Now if speed is constant, it stands that a part of these 70W are converted to vertical motion (the rest lost to heat in many forms). This is where I don't dare to understand thermodynamics enough to even make an (un)educated guess of how little of those 70W are converted to vertical motion.

Yes, I edited that when I reread the article.

The conclusion drawn from the article is that the 70+W is vibration of the bike that is damped (lost) in the rider's body. Adding suspension by running supple tires at lower pressure reduces the energy required to go over the rumble strips (https://www.renehersecycles.com/myth-16-higher-tire-pressure...). That one compares 26mm tires at 75 vs 95 psi, but there's a page somewhere that I think shows wider (think 42mm+ tires) at more like 25psi.

I had quick look around and it doesn't seem to be an actuall scam.

They have them out in the field selling small batches and there is no telltale 1 million $ kickstarter promising rocket bike powered by solar and wind pressure.

This device seems to be capturing a kinetic energy and storing it in the springs that release it to assist/smooth-out peddling? In a test clip a guy pushes down on tire and the lifts the tire and it spins ligthly. Akin to a gently push you would give to spin a wheel when fixing it and checking if its aligned (actually its less force then that).

I wonder how much of assist energy it really generates and if it makes any difference.

> In a test clip a guy pushes down on tire and the lifts the tire and it spins ligthly.

Doesn't this happen with any bike wheel? If I give a wheel a near-imperceptible horizontal nudge just as the wheel lifts off the ground, a bike wheel should be frictionless enough to move at least that much.

Rewatch that clip: he never lets the wheel do a full rotation, and once it turns 180° it starts slowing down, and then for the second demonstration he rotates it some more so that the same part is back at the top. It's not a power source, it's a pendulum.

edit: and while there wasn't a $1 million kickstarter, there was a $60,000 "flexible spend" indiegogo, which is an even stronger telltale for a scam.

That's possible; there's energy when you sit down, but not just for "being sitted down", only when sitting down or standing up. Having a look at the "how it works" website and how they claim it's energy just because of your weight I double down on a scam:

https://www.superwheelsystem.com/how-super-wheel-works/

If it was as claimed, you would be able to put this in a circular road, add a lot of weight and then have a motor provide N watts of power and get out M > N watts of power.

I think that as you pedal you shift your weight, also wobble a bit, and any uneven road surfaces can be harvested theoretically by this.

This doesn't create free energy it just captures inefficiencies created by transfer of energy from your muscles to the wheel.

But there is no free cake. This can't work by just sitting still at it :)

Also 30% improvement sounds like a outright lie or marketing PR talk.

Anyhow even if real i dont care about +300$ wheels.

I have trouble making sense of this. What is the mechanism at work here[0]? Is it maybe storing energy that otherwise would be lost (e.g. from shocks, jerks, up and down motion of bike and biker while pedalling?) in the springs to convert it into useful motion, like the Achilles tendon helps humans to walk more efficiently [1]?

Being a physicist, the name of the tech ("Weight (Mass) to energy Conversion Technology" [2]) triggered my BS detector pretty hard but I would like to give them the benefit of doubt.

They have a Twitter page with lots of close-up images of the wheel [3]. There is one with a sketch of forces at [4] which might give insight into their reasoning (which does not necessarily mean that it is correct).

[0] https://www.superwheelsystem.com/how-super-wheel-works/

[1] https://en.wikipedia.org/wiki/Achilles_tendon#Other_animals

[2] https://www.superwheelsystem.com/

[3] https://twitter.com/thesuperwheel/

[4] https://twitter.com/thesuperwheel/status/1275715365570588672...

The video shows elastic potential energy being converted into torque in the wheel as the wheel slides vertically down (due to gravity, without springs). The springs help center the resting state. Yes, it looks to me like it's trying to convert the energy wasted in damping into torque. The effect ought to be more pronounced on bumpy terrain and negligible on smooth ground.

Even on a smooth ground you move your bike up and down as you press the pedals. If you could turn some of that pulsating motion into a torque you could have some gain.

This happens only if you are riding a bike with suspension. In which case, it's still less efficient than not having suspension in the first case. (Racing bikes do not have suspension because of weight and the inefficiency.)

The idea seems to be you have a loaded spring at the top of the wheel as it’s rotating forward. The spring is loaded through some mechanism in the axle, which seems to be some sort of fixed axle that loads the spring through weight. As it rotates, the mechanism which forces the spring closed through downward gravitational force ceases to apply, allowing the fixed axle to unload that spring into the unfixed axle, which propels the wheel.

It’s no more than a rotational gas spring. The same principle that lets you open and close the hood or trunk of your car with ease. At least that’s how I’m understanding it...

There's something fundamentally missing from that explanation, because it doesn't explain where the energy is coming from. You can't load a spring without providing energy, and gravity cannot provide energy in a steady state system.

Then how does it assist for gas springs? The reason it _isnt_ hard to push your trunk lid down is because gravity is helping you do so. If you take that gas spring off the trunk, suddenly you need a lot more force to compress it.

I don’t understand your explanation: you can’t load a spring without energy, gravity + mass loads a spring, but gravity + mass isn’t energy. It is literally potential energy isn’t it?

So in the trunk lid example, the energy that helps raise the lid was stored in the spring from the last time you shut the lid. The gas spring provides resistance on the closure, and assistance on the opening.

With this wheel, the energy that goes into compressing the 12 o'clock spring must be provided (partially!) from the expanding 6 o'clock spring, plus additional energy from the cyclist to cover the mechanical losses in the system.

I don't see any left over energy that can be used to help with forward propulsion. Maybe on very rough terrain it helps out by trading forward velocity with assistance up a bump, then trading the gravity on the other side of the bump to push forward again. But that's a far cry from the claims being made on the page.

Initially I thought this was some kind of mechanical regenerative braking. I wonder if that's been attempted before.

Applying the brakes would wind a spring and bring the bike to a stop. Then applying force to the pedals or manually pulling a lever would release the spring for an assisted start.

Edit: Here's some mechanical regenerative braking projects:

https://m.youtube.com/watch?v=yK7fyugbe6o

https://m.youtube.com/watch?v=DoaJK39Tl60

Electrical regen is probably cheaper and lighter.

That was my expectation from the title as well. I thought it would look like an over-sized mainspring from a watch (https://en.wikipedia.org/wiki/Mainspring).

There was a small company back in the 90's or 00's that was developing very high rpm flywheels to store energy but they weren't able to work out a licensing deal with the car manufacturers.

I always thought the F1 kinetic energy recovery systems (KERS) were a pretty neat mechanical solution. Probably way too heavy for bikes & low-torque humans, though.

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

Spring regen is hard because you need a very big Spring to store the energy of 80kg of bike at 30mph.

Maybe air compression would work better?

Tom stanton a great youtuber builds and tests prototypes like these. Here he tried electrical regen

https://www.youtube.com/watch?v=-suxSqrP_X4

So if I understand this correctly, it uses the downwards force on the wheel when pushing down on the pedals and converts that into rotational force on the wheel.

Now, because of that annoying thing called conservation of energy, this means that you'll have to put this energy into the system by pushing down harder. I guess this translates to a feeling of sitting on a spring. That doesn't sound like very efficient pedalling.

I don't claim to understand the mechanics involved, but I think it's the equivalent of regenerative braking for suspensions. Instead of wasting the energy when you cross a bump, it stores it and converts it into forward motion.

Pretty smart if it's so, and depending on road conditions I actually see it as having noticeable effect. Especially considering how crazy people are about upgrading their bikes.

No. Not when pushing down on the pedals. Your natural weight would be all that would be needed to load the spring. At least that’s my understanding.

Sure, but when would the spring unload? You need to lift your body up do be able to load it again.

How can such unscientific stuff end up on first page of HN?

Or did I miss the part where the inventor published a breakthrough technique that allows his system to break known laws of physics?

It's entertainment! I don't laugh often. But this made my day!

This doesn't work. It is a scam. On a normal bike, imagine hooking springs up to each spoke. How far does each spoke move from its position relative to the hub during travel? Basically not at all. The recoverable energy it is almost nothing at all. Certainly not worth the extra rotating weight.

While this particular instance looks a bit unbelievable (where does the stored energy come from?), I wonder if there's more unrealized potential for spring-based energy storage.

I'm reminiscent of a sci-fi book someone on HN recommended to me the other day[0], "The Windup Girl". In the post-climate-catastrophe world depicted there, there's scarcity of energy sources; no energy-dense fuels to power modern technological civilization. The society described in the book instead learned to rely on gravity and mechanical energy, stored in springs big and small[1]. Small springs were used as portable batteries, and everyday technology was ruthlessly optimized to be as energy-efficient as possible.

I wonder how much space for this kind of innovation is there to be have? And with modern electrical batteries, is there even a point to storing mechanical energy and avoiding the mechanical -> electrical -> mechanical conversion flow?

[0] - As another biopunk novel to read after Change Agent.

[1] - Small springs are wound manually, but one biopunk part here is the use of beasts of burden, genetically engineered for maximum efficiency of converting food to mechanical energy, to wind up large springs and power other machinery.

> "use of beasts of burden ... to wind up large springs and power other machinery"

Needn't be just beasts of burden. People used dogs to turn roasting spits - https://gizmodo.com/medieval-kitchens-used-a-specially-bred-... .

IANA genetic engineer, but plants -> alcohol/biodiesel -> power seems likely more efficient than plants/feed -> animals -> mechanical energy storage -> power.

If this worked, once you start the wheels rotating, you could take your feet off the pedals and just let the superwheel force accelerate the bike until air resistance balances the superwheel force. They don't seem to have a video of that.

In a closed system how can you increase efficiency without decreasing any of the energy losses. I don't get it?

You don't, you'll just end up riding on a spring-y bike and put energy into the system by pushing on the pedals a bit further than usual relative to the ground.

Would love to hear the opinions of some actual mechanical engineers.

Can these springs really passively get you +30% efficiency? What about weight? Cyclists are obsessive about reducing rotating mass, and these wheels seem to be seriously chunky.

Is this actually a thing that could work?

The springs are compressed as the wheel rolls forward. this means added rolling resistance

Those springs are then decompressed either into another spring inside the drum, or back into the wheel again.

if its option 1 where the springs we can see are decompressed into a central energy store, it might have some application for allow easy starting (ie you press a button and the wheel lets out all its stored energy and spins. taking you from 0-10mph)

If its option 2, then you are just making heat. the springs are compressing at the expense of forward momentum. when you roll forward not only do you have to overcome friction, but also compress a spring at the same time.

If you have another spring on the other side decompressing at the same time, then you get _some_ energy back, minus heat, losses in compressing the spring in the first place, and any other mechanical losses.

In short, its a recipe for a boat load of extra friction/rolling resistance. Which will slow you down.

Let’s say you have two boards end to end, each on fulcrums, angled up like an A. Leading to the apex of the two boards, you have a platform at about the height of the apex.

Now let’s say you to take a step forward off that platform onto the apex of those two boards at the same time, pushing them down and lifting their ends. Do you have to expend any additional _forward momentum_ energy to take that step?

Now let’s say there was a big spring between the opposite ends of those two boards, and that spring just happened to compress at a weight a bit lower than force generated by you stepping onto the apex.

Now, imagine stepping off the apex. As you do, you feel the apex rise and push your leg off.

Now apply that mechanic around an axle, and use mechanics to ensure only the springs nearing the top of the axle (as it rotates) compress when downward force is applied to the axle itself. That’s as good as I can describe how I understand it, and I can’t see how it violates any physical laws. It’s just a clever use of springs.

Yeah, not many cyclists would add 10kg to their bike, typically resulting in doubling the bike weight.

I mean, TANSTAAFL, right? Does this store some energy when you slow down to release it when you start up again? That would somewhat flatten the energy expenditure curve, which may be a bit more efficient. It would imply that lifting the wheel after you've stopped releases that amount of energy (it seems to do so).

> It would imply that lifting the wheel after you've stopped releases that amount of energy (it seems to do so).

Notice, however, that the springs are actually missing when they show this in the video! Couple that with the fact that he rotates the wheel by hand to a certain position before setting it down, and its evident that the rotation we see is just due to a very imbalanced wheel.

No. There’s no 30% gain to be had. Losses in a properly maintained bicycle are already far lower than this.

> Losses in a properly maintained bicycle are already far lower than this.

Plainly not true. If I cycle a 1 mile lap and come to a stop, I have put in lots of energy yet am in exactly the same position I started in.

Bicycling (and most forms of transport) are 100% losses when considered in an "energy in Vs energy out" way.

if this is seen in bike competition, its legit. If it is forbidden, nothing can be deduced about it and if this is allowed but not used, this is useless.

There's a lot of stuff in competition that's not legit.

It looks like the ad for those meter-cheating gizmos from 25 years ago. "No one thought of using springs to save energy, but we did! Buy now and get our pro spring with extra winds for the price of a regular one!"

"An Ireland-based entrepreneur is claiming to have invented a power-assisted bicycle wheel that doesn’t use batteries, doesn’t need charging, is not speed restricted and has an infinite range." AKA Perpetual Motion

Well, a spring is a battery. You charge it by compressing or stretching it. I think this battery stores vertical motion - from when you first get on, and maybe if you go over bumps.

But the "infinite range" thing is nonsense.

Ironically, about the only vehicle that actually does meet all those criteria is a standard bicycle.

Deceptive marketing, but it’s actually a brilliant suspension. Just looking casually, it appears that the ratchet mechanism is used to convert an oscillatory energy into a mechanical energy. Most suspensions just turn it into heat.

It may make more sense by analogy to an electronic rectifier. The ratchet is like a diode and the spring is like the capacitor.

The energy still comes from the legs, but it helps capture losses. I can think of a lot of ways to improve it, and make it simpler, but it’s the first time I’ve seen something like this actually built.

Someone should call Paolo Bacigalupi

Thank You for reminding me of the Windup Girl! However this doesn't seem to use energy stored in microscopic springs.

Instead of an electrical charging socket you recharge the spring by pachydermal power?

> The action/reaction force caused by weight compresses the springs in the upper section of the wheel and decompresses in the lower section. Using the centre as the pivot, this converts energy and reduces the frictional force in the opposite direction and facilitates the rotation. Using 10kg active weight, the mechanism is shown to generate a moment ranging from 7.3Nm to 7.8Nm.”

So perpetual motion machine?

Probably not. It seems the energy comes from you lifting yourself up whenever you push down on the pedals. With this thing it'll just be a bit harder to do that.

It's certainly got the sound of one. Describing the technology as "weight to energy conversion" is particularly suspect.

The only way I can make sense of this is imagining designing a bike that is propelled forward not with pedals but by rocking it up and down.

I would mount wheel axis on a small crank and use rotation of the crank to rotate the wheel.

Something like this https://youtu.be/48TdMKCOrmo

Not sure where the springs should come in...

If this really worked and made such a drastic improvement why not get one of the plethora of bike power meters available on the market and show the needed effort to maintain a set speed with this wheel and without?

Also, if this really worked as described it shouldn't matter if it's on the front, back, or both wheels. So why not show that?

I expected mainspring based energy storage device but it looks like a typical perpetual motion machine fraud.

Meta: How did this obvious pile of pseudoscience even make its way to HN top 10?

I was immediately triggered by "Weight (Mass) to energy conversion technology". I guess a better name to call it is "Nuclear Powered BS wheel"!

Too bad such BS end up on top stories of HN

>> "We have requested a SuperWheel to test and will report back."

I look forward to reading that. Cycling magazines usually do a fairly rigorous evaluation of new tech in their articles.

...*used to be "obsessive about rotating mass".

GCN: https://youtu.be/0QDnUkUaQfk

See also YouTubers Hambini, Peak Torque and Durianrider (on a tech day) for more cycling debunkness.

Also, amongst others, it'll be a real pain if YT's ad policy drives these guys away. Well, not for the cycling industry, and associated lapdog journo's.

Apparently the designer of this bike has no knowledge of physics.

Finally, spring powered Trains and rockets like in Syberia.

It is patented according to the article. Lot if guessing here how it could/should work, but maybe someone can track a link to the patent first?

I tried tracking down the patent, the creator seems to have terminated their application in 2018: https://patents.google.com/patent/GB201703765D0/en

Good one! So if there is no patent then it might not even work theoretically, according to their own findings? Meaning this might be a hoax.

There are these things called "bumps in the road" that redirect horizontal momentum into vertical force. It's why cars and bikes have suspension. What do you think pushes against a gas shock? Vertical force. This wheel captures that force in a spring and dissipates it through torque instead of just compressing gas in a cylinder. I don't see why it wouldn't work.

This dude just reinvented the wheel.

My only question is how effective it actually is. 30% is a lot.

I'm quite disappointed in the comments I see about this spring wheel. Only a couple commenters seem to be actually thinking... Tsk tsk.

I'm not buying it. This sounds like sonic charging, or worse.

It claims to be "weight assisted". Yeah, that's not how it works.

Looks like a great deal! ...for the seller

I take it also quacks when it rides. It's the only way this would work.

> entrepreneur says X (that they're selling) will revolutionise Y

Ah, so advertisment.

WTFITS...

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