About a year ago, we wrote about the Super Wheel
, which claims to revolutionize our understanding of cycling efficiency by providing pedal assistance without using a battery or motor. Now, the design has moved forward and Super Wheel has shown more prototypes online, but we remain thoroughly unconvinced.
Super Wheel has remained somewhat vague about the actual mechanisms that supposedly provide this boost, which certainly doesn't exactly help the project's credibility. Still, it seems Super Wheel is attempting some transparency, and recently posted on Facebook
, "We will begin the technology disclosure of the SuperWheel - Weight-to-Energy Conversion Technology (WTECT). The 4 mm gap between the inner hub and external hub meant [sic] the weight causes the spring compression and decompression at 12 o'clock position +4 mm and 6 o'clock -4mm, total spring compression at 12 o'clock position 8mm, and the energy conversion continue [sic] throughout the rotation."
Is your head spinning yet? Good, because the Super Wheel isn't...
The WTECT purportedly works because it harnesses vertical movement, caused by a rider's weight, and turns it into forward motion. Somehow, apparently, the springs compress at the top of the cycle and decompress at the bottom, using the potential energy released as the springs decompress to spin the wheel. (Now, how is that energy not recaptured by the springs compressing at the top? If Super Wheel has figured that part out, it's unclear.) In some ways, the idea seems similar to the claims about Slingshot
bikes back in the day, which some said could harness vertical movement with their spring-and-cable situation and use that energy to create forward propulsion. That claim of "sling power," to my knowledge, has never been substantiated.
The latest prototype looks to have nine, rather than eight, springs, and claims to give more assistance than the last version. Super Wheel also plans to develop a version for cargo bikes, alongside its current effort to create more efficient wheelchair and recumbent bicycle wheels. There's also a front wheel in development, which is smaller and lighter than the rear wheel and makes the whole situation seem even more perplexing, and even a Super Cycle, which will supposedly be developed this winter and will be an entire bike based around the concept of Super Wheels. Super Wheel has certainly been busy.
Founder Simon Chan, who was born in Hong Kong and now lives in Ireland, said the original version made bicycles 30% more efficient, and he continues to set his sights even higher. It's very unclear where that 30% comes from, as there's no public documentation of any testing whatsoever and, given how efficient bicycles already are, it would be highly unlikely to make such a large gain from a simple wheel swap. A well-maintained bicycle is quite efficient, with the drivetrain efficiency as high as 98.5%
, though of course there's significant energy loss to rolling and air resistance.
Maybe I'm missing something, but it seems like there's more definitive efficiency to be gained from raising that seat a couple of centimeters.
To give the technology a slight benefit of the doubt, we know that technology exists that uses springs to harness and release energy, generating motion - think of a trampoline. A trampoline, of course, relies on the input of a person jumping on it, just as this wheel, in the alternate but maybe slightly possible universe in which it works, relies on the energy input of a person pedaling a bike. A trampoline, however, works thanks to Newton's third law, which states that for every action, there is an equal and opposite reaction
combined with Hooke's Law, which states that the force needed to extend a spring is proportional to the length of spring extension. For that spring extension, there's an equal and opposite reaction: the trampoline effect. It would be cool, of course, if something similar could be harnessed in the Super Wheel, but if that's the case, it'll take some more convincing for me to believe it.
The Super Wheel has been granted patents in Australia, China, Japan, the United States, Canada, and with the World Intellectual Property Office. The European Union patent is set to be finalized in December. Remember that a patent doesn't validate technology's efficacy, only its originality.
We'd all be eager to see an independent test of the Super Wheel, and we here at Pinkbike humbly volunteer Mike Levy to put it to the test.
More information is available on Super Wheel's website
, along with the option to shop, if you're feeling very, very lucky.