I clicked on the link in the OP and was reading the article.
This crankset will make you faster in Zwift. As long as you use the power from a Taxc Neo.
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Found the white paper⌠really does just seem like they have proved that the pedals report lower power when fitted to bendy cranks?
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That doesnât make any sense. The relationship between power measured at the cranks and output speed is a fixed quantity. You canât produce the same output speed with less input power through the same downstream drivetrain. It doesnât matter how you input that power through the cranks, it still requires the SAME power to achieve the SAME output speed.
The only way this could be perceived as being more efficient is if the rider somehow finds it easier to generate the SAME power through the pedals with the springy cranks. For instance if the rider could put out the required 197.2 W with a consistently lower HR/VO2. But to say that less power is required to achieve the same speed is complete nonsense if this is what they are actually presenting here.
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Yeah I think thatâs bad too! I would want to be seeing higher power and road speed for similar VO2 if it was actually more efficient. Lower measured power for the same road speed simply suggests that the power measurement is wrong! Similar V02 for the same road speed just supports the notion that the power measurement is off.
But I havenât read the paper, so I may have misunderstood their method and logic here.
Donât spoil their marketing mojo.
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LOL. Actually I quite like their concept of attempting to âsmoothâ out the applied torque over the complete pedal stroke. But it appears that they may have incorrectly measured the potential performance gain. Although to be fair it might just be that Road.cc have misquoted them, so I would need to read their white paper to be sure. Maybe they should combine it with oval chainrings for maximum effect! Or just accept that it doesnât really matter whether or not you âsmoothâ out the power transmission.
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Smart people, please educate me.
Why would you want to smooth out the torque over the complete pedal stroke? Why would that be optimal? Or said differently, whatâs the issue with having legs work as pistons, with the torque peaking when the knee and ankle/spindle are in alignment? Doesnât the momentum resulting from the torque peak provide sufficient âleewayâ to allow the cranks to then move somewhat freely until the other leg is in good position to push down again?
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Yep.
Maybe itâs good for training. For raceday, you fit a normal crankset, and, magic, youâre 4% strongerâŚ
It reminds me of those kinked cranks someone once invented.
It worries me that a lot of the claims talk about the measured power difference between the pedals and the hub - but that has nothing to do with pedalling efficiency.
Assuming perfectly accurate power meters then any difference between pedal and hub measurements is losses in the drivetrain - if the cranks are causing these two measurements to differ it can can only mean that it is causing one of them to be inaccurate or somehow changing drivetrain efficiency.
The way to test if these are beneficial would be to to get participants to perform some kind of power test - like a ramp test - if the cranks add 4% on to my FTP (measured at the hub where it matters) then Iâm in 
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As an automotive engineer, i call BS.
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No I donât think it will even do that - just make you slower if you choose to record from your pedals 
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At the risk of fighting marketing BS with more marketing BSâŚ
This from Favero could explain why bendy cranks could effect power reported by a pedal based power meter other than the assiomasâŚ
âDiscover IAV Power System | Accuracy | Assioma | Favero Electronicsâ https://cycling.favero.com/blog/tech-tests/whats-iav-power
Non of this disproves the claims made by the magic crank manufacturer but does show that the method they have used to test it is flawed.
Yep, this is highly debatable in its own right. Especially as you would actually have to increase the force applied on your downstroke to load up the spring.
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That was my first thought too. They seem to be getting confused between drivetrain efficiency and human pedalling efficiency.
Having now briefly read the papers, it continues to look like a very dubious result. They are basically claiming reduced input forces at the pedals for a given output power. So you put less force onto the pedals on the downstroke, but you get the same power output because of the sprung crank arms returning stored energy on the upstroke. Iâm not really getting that part. It seems at odds with basic physics as I know it. I do get that it smoothes out the power transmission over the whole pedal cycle, but Iâm not sure how you can get the same torque/power with less input pedal force. I guess they are suggesting that you are wasting more energy by stomping on your pedals vs a smoother input pedalling circles.
I think the idea is that the power you would normally lose on things like pulling up would help reload the spring like componentâŚ
I think they are trying to do a Nike-carbon-fiber-plate-on-running shoe thing.
The weight on the landing recharges the springâŚ
RightâŚ.but in the case of shoes (as noted above) you have gravity which is loading the springs. In the case of these cranks, it is energy you need to input yourself. And since energy can be neither created or destroyed, their concept doesnât hold water, IMO.
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I didnât said they were going to be successful.
I just said they are trying⌠and I think they will fail.
They are trying to effectively do a perpetual motion machine⌠and at this time, we have no way to do thatâŚ
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The thing that makes me wonder about stuff like this is that it makes you wonder why arenât prototypes setting world records. A carbon crankset is not that hard to make. How much would Ineos, Ganna, Rohan Dennis, or any top Olympic pursuit team pay for a 4% gain?
This sounds vague like that old article claiming that noodly frames climb faster because of a âplaningâ effect.