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Hmm, cool design concept but you are just replacing friction for electromagnetic drag
I also wonder how sensitive it is to distance from the rim - I suspect its going to be a square or cube law, someone who did decent level physics will know
fidbod-
Same tech as the Magnic light that was made a while ago I think.
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The field from the eddy current itself (effectively a current loop within the metal) falls off as the cube of the distance (assuming you're on axis - let's be generous. Reference). As the field inducing the eddy current will be coming from a permanent magnet with a (roughly) bar-like geometry it will also have a cubic dependence (reference), so you get a 1/r^6 dependence.
I believe the technical term for that is 'brutal'.
Emyr
hamrack
Saw this through looking at Kilo, a danish design agency. Felt compelled to share. I definitely can't see myself going for this kind of thing, but I wonder whether the fact that people think a dynamo will cause loads of friction etc will push them to back something like this/ create a market for similar products.
I mean I certainly can't see it happening in Scandinavia (do they all already use dynamos?) But maybe in US/UK.
https://www.kickstarter.com/projects/1651132789/neo-worlds-most-powerful-friction-free-bikelight