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Green Wheel - 3 in 1 wireless electric bicycle hub motor


February 23, 2009

MIT's enclosed GreenWheel system

MIT's enclosed GreenWheel system

February 24, 2009 A fully self contained bicycle hub motor known as the GreenWheel has been developed by students at MIT that contains the motor, batteries and motor controller all within the hub enclosure. Very similar in concept to the E+ we reported on earlier this week (which we have been informed by a reader is a reincarnation of a Wavecrest Electric bike), but taken one step further by combining the batteries together with the motor in a single hub instead of putting the batteries in the front hub and motor/controller in the rear hub as on the E+.

The only external part of the GreenWheel system is the handlebar-mounted throttle that is connected wirelessly to the electric motor in the wheel, so absolutely now external wiring is required along the bike frame. The hub motor is spoked into a standard bicycle wheel and is powered by Lithium ion Nanophosphate batteries supplied by another MIT firm A123 Systems.

The potential advantage of this enclosed system is that if you want to give your bike an electric boost, you only need to change the wheel, not purchase a whole new steed.

No details on motor power output or battery capacity have been made available but range is expected to be an estimated 25 miles (40 km). Pedaling the bike doubles the range under electric power provided the rider isn't traveling at the nearly top speed of 30 miles an hour (48 kmh). The bike can be charged by pedaling or by plugging it into the electric grid. A123 batteries can be fully charged in only 10-15 mins.

Both front, rear or both wheels on any bicycle can be powered with a GreenWheel and the team estimates its range at 40,000 miles (64,000 km), or about eight years work of travel at an estimated 20 miles (32 km) per business day.

Paul Evans

Via Treehugger via Discovery Channel.


Very cool packaging challenge, especially if it can be done without too great of a weight, performance, durability and price hit.


So to recharge at work/home you need to take off the dirty chain and carry the whole wheel assembly up with you ?? Not very practical....


I am amazed how the realisation that oil is finite, has caused a literal explosion of new technology,,,,,,,,it is a pity we could not have realised this 50 years ago but of course the oil barons ruled the roost then


sutski123, if there isn\'t a power point near your bike park make sure you take the front wheel option mentioned. Its a much easier and cleaner replace and refit process than the greasy chain option you mentioned. Now how much will it cost ?

Facebook User

Out of interest how long does a full charge last if you pedal as well. 50K 100K 200k?

Peter Coulson

Copenhagen Wheel?


I love the concept - can\'t wait to see solutions thermal management.

Adam French

It looks neat, but its a load of crap to me because the article won\'t tell how much it is, or where to get it. I\'m interested in electric bikes, but most of them are either 200lb pigs, or $5000. BS! Buy a gas bike. And there is plenty of oil if we quit letting useless eaters burn it!


Cool comments here guys.... Gette Bikes in Australia solve a lot of these challenges though. Check it out www.gettebikes.com


While some may think packaging is important, neatness, all in one and all that....I have a question. What hsappens when some pidling part fails? Do ya get to repurchase the whole farm? I think the less sleek but owner friendly setarate components is a better strategy and have sworn to only build that way. That allows mass lead battery packs today and light high tech when its afordable to more consumers. Its also more amenable to 3rd world consumers who may have to make do in more ways than our well codled \"take it to the shop\" elites are. Well, anyway, there are also issues imbeded in that like the durability of having the motor \"shafts\" and the road hazards \"axle\" be the same pieces. Want to regularly take apart and degrit yours???

I must thank you, ChelC, for the links to Gette Bikes from Down under. This is the superior approach from an engineering perspective. The motor is at the same rpm as the crank you pedal. The cadence is what we love to keep constant, and the speed is determined by the gears, not how fast we can spin the cranks. The motor finds this most efficient also and both motors are happiest with this marriage of their efforts. Batteries have endorsed it my lasting longer without those extremes of amperage found with hubmotors. I just wish Gette had more than about 1/4 hp. Not that it does not double my aging output, but work bikes could use much more and stay reasonably slow...lane...alternatives....For the home tinker, a neat game might be adapting the gearmotors feom wheelchairs. I wonce saw the whole chair- batteries, charges, 2 motors and the rest- for $100 at the local donated goods store. Unfortunately I had no idea of how to use the motors and passed. Personally my mission is to increase pedal vehicles my getting people out of cars who would not consider returning to diamond framed 2 wheelers, by getting them out of cars and INTO ...2 and 3 seaters even! low kinetic human hybrid.com


Great! When can I buy this?

Facebook User

This is a novelty advance that is less practical but still is a proof of concept. There is no real point in using fewer batteries in order to hide them from sight. We want a more dependable sized battery pack, a spare and be able to swap them out on the go or when getting home. We want things that are both practacle and affordable. Disc motors offer the best efficiency,,, approaching 97% There is no reason a person cannot buy his own hub motor, his own controller and own batteries and make is current bicycle a hybrid. Look at What RC plane builders do all the time, they are some of the most crafty people in the world and they can do it all with off the shelf products. I hope more people in the future become DIY people to challenge the new breed of engineers to be more practical.

Ronald Cooper

Ohh its a awesome concept, can't wait now!!! thanks for sharing with us.

Facebook User

How is the project progressing? When will GreenWheel be on the market? Is there an update on the project?

Sam Calvin

i want two please!

John Parkes

Electric assist bikes are already selling well here in Japan and have been here for a long time. Folks have not really shown interest in the states yet for them to get the good stuff.

Jerry Carroll

I was looking into changing aYamaha FS1E to electric power This looks like a great way to do it. I found out a few details relevant to this for UK use at least, it must weigh less than 40KGs all up and it must not be capable of more than 15 MPH though not with an \"off road\" booster switch which would sadly make it illegal; also it will need insurance thats if any insurers take them on yet though a driving licence will not be required and the road tax will be free but a disc from the DVLA to this effect will still be required to be displayed. now where are my scales.........


I continue to see many efforts to produce different electric motors for bicycles. But to my mind a low cost production velomobile with electric motor is the only real logical solution to daily commute. A velomobile is a completely enclosed cycle, usually 3 wheel. The aerodynamics make it very efficient. It has lights and can be ridden in rainy weather even in snow (they have them in Norway). Most of them are made in Europe and are very expensive even though they have less and fewer parts then a car or motorcycle. For the very lazy I could see a version where there is no pedaling mechanism. Which would simplify manufacture. I suppose in 20yrs something will be made like it for way to much. But for now its electric motor on old tech bikes and super expensive electric\"cars\" even though most vehicles carry only 1 person. I hope to get a 3d printer someday and print my own velomobile....

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