Batteries Published on August 18th, 2011 | by Jo Borrás 9 DIY Flywheel Hybrid Bike Boosts Without Batteries (video) Tags: bike, bike lanes, bikes, built, capacitors, commutermtech, commuting, DIY, engineering, home, HPV, human power, human powered technology, storage, student, tech About the Author Jo Borrás I've been involved in motorsports and tuning since 1997, and write for a number of blogs in the Important Media network. You can find me on Twitter, Skype (jo.borras) or Google+. Related Posts Israeli Man Converts Box Truck Into Solar-Powered RV → DIY Tea Lighter (VIDEO) → Team Austria Takes First Place At Solar Decathlon 2013! → DIY Cleantech Resources → Pingback: Flywheel Energy I: Safety, Security, Reliability | CleanTechnica Jmsthurber I wonder if the flywheel couldn’t be fabricated from a lighter material, such as plastic or fiberglass. This could make it a lot more effective. Carl Sagan actually, decreasing the mass of the flywheel will defeat the purpose, as it will also decrease the amount of energy the device can store; making it less effective. it’s all outlined here: http://en.wikipedia.org/wiki/Flywheel#Physics Jeremy R another 2009 flywheel BIKE project, much more pretty too: http://www.nytimes.com/2009/12/15/science/earth/15bike.html Jo Borras The Copenhagen wheel was super-promising, but hardly accessible to DIY-ers. Anonymous Good idea BUT, it’s a bit half baked. To get the bike moving from a stand still, as you pedal you are inputting energy into the flywheel. That’s extra load!! Just use an electric hub motors and a battery. The battery won’t need charging with pedal power before it can be used! Jeremy R The flywheel stores the breaking energy into spinning, and it is harvested when the rider wants to speed up again. In a short number of stops and restarts the weight of the device is offset by the reduction in waste that normally is lost in breaking. However if you never break, flat land and no red lights it is a considerable amount of weight to add to the ride. Jo Borras Correct. This isn’t for roadies, but bike-messengers (for example) would probably benefit from it. Jo Borras No, not with pedal-power – just with electricity from the coal-fired plant down the road.