Biking has many benefits not only for the environment, but also for your health. But for a lot of people biking becomes a challenge for the amount of energy needed to do it, especially in roads that are not designed for it.For this reason, some researchers from MIT, developed a device called “The Copenhagen Wheel” , that conserves the energy that you already spent, and uses it when you need it most. The result: Hills become flat!!
For More info:
http://www.youtube.com/watch?v=S10GMfG2NMY
http://sharepowered.com/community/copenhagen-wheel-mit-bike-invention/