I’m no engineer, but something, or everything, about this just seems kind of suspect. Thoughts from the more educated in the community?
7 for the interesting design, 0 for looks
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It’s real as in that it exists. As for accuracy? I have my doubts.
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Considering they can’t put a chain on the correct way I fail to see how they can measure anything from it correctly.
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To be fair they do say that it isn’t compatible with srams flat top chain…
Didn’t know sram did a flat bottom chain though 
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Flat bottom chains are a new development. It’s also apparently not compatible with sram flat top chains so not sure why they decided to demo it using that system. Nothing they have showed so far makes me have any confidence in the product.
Flat bottomed chains, they make the rockin’ wheels go round!
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I’m struggling to get my head round how exactly this works.
The way they casually state that they use strain gauges to measure the tension on the chain and how that is somehow equal to “torque” (which is different) sort of makes me wonder if it’s worth my while.
It isn’t.
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I really really hope they send a unit to GPLama for testing. I can’t imagine it will do better than his favorite dual sided shimano power meters.
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Tension in the chain times the radius of the ring equals torque. It looks like it measures chain tension similarly to how a spoke tension gauge works. Fundamentally, it looks like it could work. Practically, there could be a lot of issues.
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Sorry I was being a bit pedantic.
This is the bit that I took issue with. Where they call the power equation simple but then write it down half in half linear and half angular form.
It’s either
Power = Torque x Angular Velocity
Or
Power = Force x Velocity
But yeah, it’s the measuring the tension on a moving chain with 1% accuracy without causing friction that has got me most confused.
I’m amazed that 900 people would send them $225.
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It’s not even that cheap. Normal price at 300 dollars? Just spend little more and go buy a Magene P515. Then have something well proved.
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Just no.
Shimano has been struggling to deliver accurate power meters for a very premium price despite being the 500 kg gorilla in the room. I’d stick to established brands with a track record.
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Hi, I am the engineer behind this product.
Thanks for your comments and interest in our product.
We are a small team of three and hired a production company to make this video. We did not install the chain, nor did we have any control over that process. This was a last-minute video due to various circumstances.
Our choice was either to scrap the entire project because of this mistake or hope for understanding - after all, we do not market the chain, the bicycle, or the actor featured in the video. None of that is what we are promoting.
I am happy to explain any details of how our power meter works, and I am glad to answer any other questions or concerns aside from the chain issue.
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Thanks for your comment.
This was written for a general audience. I am fully aware of the units and of how power is expressed, but I needed to explain it in a way that’s accessible to a broad audience. We use a chain speed sensor and a torque (chain tension) sensor, and in very simple terms, the product of these two is the power. That’s all we were trying to convey.
I have over 20 years of experience in aerospace, mechanical, robotics, and related fields, but I don’t expect a general audience to understand concepts like Euler angles, the Runge-Kutta method in numerical analysis, or the Navier-Stokes equations. Our explanations have to be simple, so we did our best to present everything in clear, straightforward terms.
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If you have multiple bikes and want to have PM on each of them, that quickly becomes expensive.