Comment by franciscop | Hacker News Reader

Comment by franciscop | Hacker News Reader

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.

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.

> 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.

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