Image of German-designed e-bike via Wikimedia There’s a new class of electric bicycles prompting oodles of attention, collecting millions of dollars in funding and providing little more than dust-collecting, spider web-encrusted racks in bike shops. Within the last five years, Panasonic and MIT unveiled e-bike prototypes, which boast batteries that can re-charge themselves through a process called regenerative braking. A regenerative brake reduces a vehicle’s speed, thus expending energy, but in the process it captures some of that lost energy and stores it in the battery for future use. Contrary to what they claimed in 2008 and 2011 , neither Panasonic nor MIT has released their design to markets. There are many possible explanations, but one that stands out above the rest is simply that the design does not work, or at least does not work well-enough to compete with e-bikes already available for purchase. This post explores some of the physics behind this design and whether
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