Environment Transportation Engineering Student Builds Flywheel Energy Recovery Into Bike By Lloyd Alter Design Editor University of Toronto Lloyd Alter is Design Editor for Treehugger and teaches Sustainable Design at Ryerson University in Toronto. our editorial process Facebook Facebook Twitter Twitter Lloyd Alter Updated October 11, 2018 Migrated Image Image credit Cooper Union Share Twitter Pinterest Email Transportation Active Automotive Aviation Public Transportation Max von Stein's flywheel bicycle is everywhere these days. The engineering student first demonstrated it at the Cooper Union year-end show. ArchPaper described it: Engineering student Maxwell von Stein applied the principles of a hybrid car to the bicycle to harness the kinetic energy typically lost when braking. With a variable transmission and a flywheel mounted to the bike's frame, von Stein's bike allows the rider to pick up speed faster after stopping than with a battery. There are a few questions that I would love to know the answer to; -is the energy saved by having regenerative braking with the flywheel greater than the energy expended by pushing around an extra fifteen pounds? -flywheels have a big moment of inertia. How easy is it to turn the bike? Doesn't it want to keep going straight? Lucas Vieira / Wikimedia Commons / Public Domain Flywheels also exhibit precession, " a change in the orientation of the rotation axis of a rotating body." It's the wobble you see in spinning tops. Does it create a problem? Neat idea.